The Second PUMaC 2009

This story begins long before Saturday, and in fact I'm writing this sentence on Wednesday. But while there's an interesting story that started far earlier, I'm going to start at the Saturday a week before the competition, when the power round was sent out. The power round this year was about lattices, meaning subsets satisfying the following properties:

• 


• If , then


• If and then

Those of you who like thinking of as an abelian group should immediately notice that a lattice is simply a subgroup of . Those of you who are reading my mind and thinking of it as a -module are noticing that it's a submodule (now of course abelian groups and -modules are the same thing, but some of the ideas later are better to think of in terms of modules).

The power round was basically then an excursion into basic results for -modules. It defined isomorphisms and asked for some isomorphism invariants, which were relatively simple. It then asked to show that all these submodules of are finitely generated, and then finally went into the canonical form of the submodules (which is better known for the quotient modules as the Structure Theorem for Finitely Generated Modules over a PID). So essentially I had made a post on this power round more than a month before it was released. Awesome.

So how did the power round go? Well basically I didn't want to do my homework on Sunday, so I did the power round again. By Sunday night, I had done every problem done except 3.5 and 5.6, both of which I knew how to do but it involved proving or citing the above mentioned Structure Theorem, or at least special cases (other teams went the citing route, I would have proven it but I didn't want to go through the entire proof). On Monday I came up with a clean proof of 3.5, but 5.6 still eluded me. Finally I gave up and just wrote up the proof...it started on page 5 and ended on page 10 of section 5 (well at the time it took up fewer pages, but we later changed it from 11 point to 12 point font and while the wording didn't change, the number of pages did).

So now that the power round was written up, I sent an email to the team telling them to check it for readability and correctness. So while Sam and Adam had checked the round fully before the Wednesday mandatory practice, the other five team members were made to read over the round, even if they didn't know linear algebra. By the time I left for school on Friday morning, this was the chart of who checked what (the initials of the team members are at the top):

Yes, I have a whiteboard in my room.

Okay, so every problem was checked by at least half of the team except for 5.7. Looks like we should be good to go for power. After printing the twenty-two pages that can be found on the wiki, I snapped the above photo and then went to school.

At lunch, the car arrangement was a source of some great entertainment. We set everything up, including a car with Grace, Allison, and Divya. Then, as a joke, we switched Divya with Lawrence to see Lawrence's reaction. Allison arrived first, and reacted with "WHAT THE HELL?" But after a few minutes, she said "Whatever, I'll have Grace's laptop with Asian dramas." XD

Then Lawrence arrived, and he also reacted with "WHAT THE HELL?" But instead of just switching himself with Divya (as we expected), he switched himself with Seung In. Somehow that stuck and the car ended up being Allison, Grace, and Seung In. I still have no idea how that actually happened.

My car consisted of Aviv, Sam, Renjie, Akshar, Jenny, and me, so we were a bit cramped in the van (Jenny had to sit in the middle of the back between Akshar and me). On the car ride, we played hearts for a bit and house for a bit. I sat out the first game of hearts, where Akshar got completely destroyed. Second game, Sam and Renjie decided to play as a team and I was in. I got to shoot once, having two runnable suits (I believe my distribution was 2056) and by leading the spades early, so that when I got the lead again I took the last 7 tricks, or something insane like that, which contained all of the points. Shortly afterward, I ended up getting the queen a few times and eventually lost, but that round of shooting was quite fun :).

Upon getting to the hotel, I was disappointed to find out that I had one of the small rooms, but it was fine. I played around with google wave for a few minutes (I had finally gotten my official invite just that morning) and realized that it was actually pretty laggy. I wouldn't want to use it for most communication in its current form. Especially big threads start to lag massively. I'm not sure what it is, but it reminds me of the lag you get when you're X forwarding. But really, if document viewers can display 200+ page pdfs without lag, you'd think that google wave would be able to handle waves with only 100 messages.

After just a few minutes of google wave and finding the latex bot (watexy@appspot.com for those of you who don't know about it yet) I went back to the lobby to wait until dinner time. We ate dinner at Quaker Ridge Mall, which is a horrible idea. There's basically nothing there to eat, except for an applebee's out in the parking lot, which we went to. The food was decent, but then Jenny tried to cheat us out of $1.50. We caught her when we ended up short a bit of money, and then she decided to complain that she didn't have any coins so she had to pay $.50 too much. I tried to give her the rest of my coins ($.03) but she wouldn't take it. This was after she decided to buy $.60 gravy...

Anyway after dinner I took my laptop up to Renjie's room where we were going to play mafia. While playing I read through the google wave API. It looks simple enough, but based on my googling javascript has unfortunately little support for dynamic graphics and I don't want to use flash, so I want to find a good way around that. The game of mafia went extraordinarily well. After the first day, where we killed Seung In for voting for no lynch, Sam and I saved Luke, who was also targetted by the mafia. Second day, we killed a mafia, and then Sam insisted on saving himself. I had no better ideas, so I shrugged and let him do it. But the best part was after the next night, when Sam wanted to save himself again. I was like man this is a pretty silly and pointed to someone else, but Sam eventually won the fight. Next day, Sam said "I think Brian is the mafia, because he and I are the medics and he wouldn't save me last night!" The game ended where, in the last night, I wanted to save Jenny, Sam wanted to save himself, and then after we agreed on Jenny, Sam said (in the middle of the night), "Wait! Do you think it's more likely that they killed one of them or one of us?" Turns out Sin had tried to kill Jenny, and I was right. Hah.
(On the other hand, if Sin believes that Sam and I are the medics, targetting Jenny ensures his loss. However, he says that he didn't think that Sam was telling the truth, so his decision is defensible.)

Anyway, it's time to talk about competition day. I skipped breakfast, as always, and we headed out shortly after our hoped departure time of 730 (Aviv was late, as always). We got to Princeton at some time which I don't know because I don't wear a watch, and then after Mrs. Gabriel registered us we started walking toward McCosh, during which I heard Jenny yell from behind me, "Hey Brian, look behind you!" I turned around and saw Sherry there, so I slowed down a little, but she stayed behind me by a bit. Oh well.

On the way into McCosh 50, I saw Amy Zhou just a few feet in front of me! But she didn't notice me. Anyway, once we got in, I decided I wanted to talk to some people, so I went back outside and went to the registration table where Damien and his team were standing. While I was there, several members of the Exeter team showed up and I talked to them. It was pretty much my first time talking to David Xiao since red mop. We talked about the power round, and I found out that both North Carolina and Exeter had failed to solve problem 5.6. Awesome, we looked to be in good shape. Good lead on all of the other teams. In the middle of the courtyard, Sherry was pacing around waiting for the rest of the AAST team, and I considered going over and talking to her, but her parents were there and I would have felt kinda awkward. So instead I just continued talking to Damien and the Exeter people. It was pretty good to catch up with them. Also that this time I said hi to Amy (she actually saw me this time), who I hadn't seen for over a year since I missed MathCamp '09 :(. Well anyway that was that for the outside talking. We then all went into McCosh 50 and continued talking. There I saw several more people that I knew, but AAST still wasn't there. When finally they walked in, I went up to the door and said "Way to be late, guys." (it was after the scheduled start of the opening ceremony I believe). The opening ceremony started shortly afterward, 5 minutes late I believe. They gave us our proctors and we headed off to our testing room. But when we got there, the door to the building was locked, so we had to go in the other entrance, up to the second floor, and then back down to get to our room. Door unlocking fail. We got to our room and sat down, informed our proctor that Sam and Seung In were switching some subject tests, and then started. Our proctor was Arthur Safira's roommate, and as he put it we "probably got the only non math or science guy" there. In any case, my first test was number theory. Many of the problems were classical, but two of them were pretty decent:

Then again, the second is pretty straightforward if you know continued fractions (and are able to compute that in the time limit, unlike Damien). Some of the problems were a bit too classical. #1 was essentially the same as a Math Prize problem, #2 was find the number of solutions to for positive integers a and b, and #4 is problem 103 in Engel's number theory section, according to Andre.

Next up was combinatorics. Again the test was mostly straightforward, although I made a few mistakes that had to be corrected. And there was the now infamous problem:

As pointed out on AoPS, the fourth largest number of the set is 2, not 4. Many people interpreted it the other way (including the test writers and myself), so the answer 606 was considered correct, rather than 303. This could have been worded much better ("When these numbers are sorted in increasing order, what is the expected value of the fourth number?" or a variety of other ways), but regardless I got the points :). Unfortunately, Sam didn't, so our team suffered a bit because of the unclarity. Darn.

At this point PUMaC's amazing grading system that would announce individual finalists immediately after team round was revealed to us. All the answers were integers, so the proctor called us up one at a time to verify that he typed in our answers correctly to an online submission interface, which presumably handled grading automatically.

So next up was the team round. I forbade the team to discuss the individual round until after the team round, because they might become depressed about how badly they had done (if they had done badly), and also because I didn't want to answer questions about individual during the team round. Team round was quite interesting, with the answer sheet being a crossword puzzle. We got everything (either by solving or guessing) except for one problem, which we had 3 out of 6 digits for, but guessed all the other three wrong. That got us a total of 93.5 points out of 100. Not bad.

After team round, we were told that we had one individual finalist: me. It was a large disappointment that none of the rest of the team made finals, but I was happy that I had qualified. I decided to not bother waiting in line for lunch at that time, and went straight to the finals room where Peter Diao was the proctor. We both kinda partially recognized each other, and then he bothered me about giving him a weird look when he said hi. Then an AAST contingent including Sherry, who thought she had no chance of making finals, walked in. They certainly had more finalists than we did, but by no means did that necessarily mean that they did better on individual, since our scores were all reasonably high, just not high enough on any one test to qualify for finals.

Finals went okay. I looked at the problems and saw how to do problem 2 pretty quickly. It was a simple bounding argument and then a bit of cleanup at the end to eliminate two bad cases. After that problem was taken care of, I looked at the other two. Problem 3 looked obnoxious (47 46-gons? No thanks), so I worked on problem 1, which was a pretty annoying analysis proof that I wasn't completely satisfied with at the end, but I figured it was okay since it looked like 1 and 3 were both hard, so I probably had about as much as anyone else.

After individual finals, Sherry and I lagged behind everyone else, where I found out that Jenny had called her twice and texted her twice during individual finals XD. Way to go, Jenny. She tried calling back, but no answer, so we just went outside and started walking around. There was still free food for the individual finalists, so I decided to take some. I then offerred her some milkis, but she declined for the time being. We found Nassau street and went to the Panera, where I had a turkey artichoke panini and she just had some broccoli and cheese soup because she had eaten the PUMaC lunch before finals. It was a good lunch, though :). Afterward, we walked around Princeton campus for a bit, getting lost because her map from google maps had very few buildings marked on it. Eventually we ran into Divya, Grace, and Allison who were "totally not stalking" us. Of course not.

When I got back to McCosh 50, Greyson said "Congratulations on number theory." Apparently I had gotten all the problems right. I then asked to see the combinatorics answer sheet, and I had gotten all of those right too! With a double perfect score, some of the results were a bit less suspenseful.

The awards ceremony needed another 10 minutes of stalling after minievents to get a powerpoint made with results, so they had the math bowl finals, where AAST had a substantially better showing than last year. And one of the questions was StarCraft! But as Damien pointed out, StarCraft actually came out in 1996, BroodWar came out in 1998. Always recheck your facts. And apparently Damien was actually wrong, so he just fails.

The way they had the divisions split probably contributed a lot to the pumctuality of the awards, though, since we didn't have to listen to all the B division awards. First up was the subject tests. Geometry, Algebra, Number Theory, and finally Combinatorics. Vlad won geometry, so I was really happy off the bat, since he was my roommate at MOP last year. Then Chong won Algebra, who I knew from MOP 2008 (where he will be forever known as stomachache) with a perfect score. Interesting difficulty level, allowing perfect scores. It doesn't really appeal to me that much, since it potentially leaves people having nothing to do at the end of a test, but that's okay I suppose.

They finally got to number theory, and I won (Did anyone not see that coming? If not, you need to read the entire post). When I went up to receive the medal, it wasn't large enough to go over my hair properly, so it got stuck on my hair and glasses, much to the amusement of the audience. Going back to my seat, the rest of TJ said I should just stay there. I decided not to take this piece of advice. So next up was Combinatorics, where I won again (seriously, if you didn't see this coming read the post). And again, the medal got stuck on my hair, again to the amusement of the audience. I now had two medals to show for my trip :) Laura got a picture of this event, which has some hilarious comments.

Then overall results. Here, because of lack of communication about the method for finals, I had no idea if I would place or not. I was especially worried when Vlad placed 8th, since he had gotten problems 2 and 3, while I had only gotten problem 2 and most of 1. But I ended up winning overall as well, completing my sweep of individual events.

Yay two medals an a trophy :)

Next was power results. We sat through places 10 through 2: Beijing STFX1, The Evil Geniuses for a Better Tomorrow, Montgomery Blair High School, AAST Mu B, North Carolina, PEARL, Albany Area Math Circle, Murph and the Magictones, and Lehigh Valley Fire. Now at this point we should probably be suspicious since AAST Mu A and TJ A are both missing, but we didn't think about it too much. As the announcer said "and in first place...", a shout from the audience came: "Brian Hamrick!" (This was from the North Carolina area, so I'm not sure exactly who said it. If anyone knows, I'd be happy to hear). "AAST Mu A"

Okay, at this point, all of us in the back right corner of the auditorium (where TJ always sits) are thinking "WHAT THE ****?" And this wasn't limited to just the TJ team: Peter Diao immediately ran off to the grading room to figure out what went wrong, since we were definitely supposed to place. We were thinking somehow one of our problems got lost, either in printing or by the sponsors, or by PUMaC themselves. We even considered that maybe they mixed up our solutions with another team, but every single page of our power round had TJ A on it, so that was pretty unlikely. Meanwhile, AAST, to our left, was ecstatic because we had apparently massively screwed up the power round.

What?!?

We sat listlessly through the rest of the ceremony, as we placed fifth on the team round and sixth overall. We all knew that we were supposed to place higher, but we didn't know how high. I know I barely could pay attention to the top rankings, as PEARL took third, Beijing STFX1 took second, and Lehigh Valley took first (who is on Lehigh Valley, anyway? They didn't do so well on team and power so they must have had pretty good individuals). After the conclusion of the official awards ceremony, we met Peter againat the front, where he informed us that our power round score had failed to be entered, and that we had actually won the power round and taken third overall. So we missed out on a huge trophy because of a PUMaC screwup. Way to go, guys. Peter said that we got 78/86 on the power round, and I asked him what the second place score was, to which he replied 74. He also said that we had only beaten the teams that were at the actual competition; the German IMO team had gotten a perfect score. (Note: I've now been informed by Peter that he was mistaken and AAST in fact got an 85 on power, so we were actually second on power and third overall. He also says he thinks we lost a substantial number of points on 5.6, which I think is completely correct, so my guess is that the graders simply didn't understand it and took off points, which has happed before, such as to Alex Zhai on USAMO. Also apparently our score was entered, but it was entered as an 11 because someone sucks at reading. Massively.)

Regardless, I was pretty happy with my individual results, and third overall wasn't too bad for the team. When we left, I realized that I still had all of the milkis in my backpack, I had forgotten to give Sherry one after we went to panera :(. I was going back home in my dad's car, rather than in the car I went up with, so I gave them six milkis because we had done pretty well and took the other six in our car. Hopefully Jenny got her milkis this time. She complained after Duke that I had given Sherry milkis and not her. Heh.

The trip back was pretty uneventful. I slept a bit but the way the seat was I had a really sore neck upon waking up. Bleh. Whatever. I got home pretty much satisfied from the trip. While PUMaC certainly still had some kinks, it was run much, much better than past years. I think the contests could have been a bit harder, since the finals cutoffs seemed a bit high (probably around 30) to have 7 and 8 point problems, and a lot of the later problems were actually pretty easy and/or guessable. But besides the screwup on power and the couple of mistakes on the tests, it was a good event, and I got some good stuff out of it.

The spoils

Failure

The second of five performance contests was this Wednesday at math team. This one went a lot worse than the last one, which I think is evident from the score distribution:

First, nobody got a zero! Why? Well, turns out that question 2 was flawed. The triangle with side lengths 5, 15, and 16 does not have an area of 72 and does not have an inradius of 4. This was brought to my attention during the contest and I decided to give everyone credit for the problem. After all, every triangle satisfying the problem statement has a side length of 1, and 2, and 56, and :). (Hint: there are no triangles satisfying the problem statement)

Second, 2 and 4 have about the same number of people! That's pretty easy to explain. The contests are set up so that there will be three tiers. The top tier consists of A teamers who are capable of solving all of these problems. They are expected to always get 1 and 2, usually get 3 and 4, and then sometimes get 5 or 6. The second tier consists of B teamers who are capable of doing well, but either don't have the speed or the knowledge to complete the entire contest in the time allotted. They are expected to always get 1 and 2 and then get some of 3 and 4. Finally, there are the lower teams who are expected to be working on 1 and 2 the entire time.

So what does this mean? This essentially means that A team has a 6 question contest, B team has a 4 question contest, and the rest of the team has a 2 question contest. When #2 turns out bad, it turns the A team's contest into 5 questions, the B team's contest into 3 questions, and the rest of the team's contest into 1 question. The impact on the A and B contests is negligible, especially since they are supposed to always solve the first two problems. However, the contest for the majority of the team was reduced from two problems to one, which resulted in the massive clump at 2 and 4.

Let's look at the test in more detail (you can see it on the wiki page linked to in the first paragraph).

The first problem is straightforward, provided that you can list the primes up to 43 and count them correctly.

The second problem is screwed up, as I said, but you can see what I had intended on the solutions page. (Maybe I should've solved for the true side lengths that would make it work so that you can also solve it with e.g. Heron's formula)

The third problem has an amusing story. It originated from a dinner at IOI when we were eating with the Canadians. One of them proposed a few problems to us. The first was a geometry problem which I can't remember, but Travis eliminated it rather quickly. Then he said "Here's a problem that took me a while to solve. See if you can do it. Find if ." To this, I responded, "Wait, isn't that utterly trivial? It's just the difference of two geometric series..." Their response? "Damn! Why didn't I think of that?"

The fourth problem has a somewhat different history. I first saw this kind of problem at MathCamp 2006 in a class titled "Calculus Without Calculus". It was a nice problem, but I basically never saw it again until last year, when it appeared on an ARML practice. However, the lines in the ARML problem were given to be perpendicular (BAD was right) and so most of the people who solved the problem simply calculus bashed it. After the calculus solution was presented, I went up to the board, drew the circle, and explained that not only could the problem be solved with just power of a point, it was independent of the fact that BAD was a right angle.

The next week, I wrote a TJML and included a similar problem, but changed the angle to something obnoxious: 82.5 degrees. The result was that one person solved the problem and nobody else, and many people didn't even realize that I had presented the exact same solution at the previous week's ARML practice.

Fast forward to the summer when I was writing problems for performance contests. I remembered this failing in the team and decided it was about time that they learned to listen to and remember solutions, so I put the problem in my database and aggressively classified it as a medium level problem.

Problem five is a classic use of Hensel Lifting. Many people commented after the contest "I have never heard of Hensel's Lemma." That was intended, but you can solve the problem without knowing Hensel's Lemma if you think of first solving the equation mod 5, then "lifting" it to mod 25, and then mod 125. This was a problem that was simply meant as a "here is a useful technique that you should remember if you want to do well" problem.

Finally, we get to problem six. This one was thrust into the performance contests because of some team contest last year (I can't remember which contest it was) in which there was a similar problem and none of the rest of the members of my team knew how to do it (meaning none of the top members of last year's math team). Again, this problem was meant as a wake-up call, so that people would learn how to approach problems like this, since they have appeared on various contests in the past (I think there was one at Duke last year). In another sense, it was a problem that said "This is something that is useful to know if you want to win." Essentially, some of my problems are problems that nobody will get, and if you know how to do them you have a huge advantage. An obvious example of this is HMMT 2009 Calculus #10. TJ A essentially got 24 free points because we knew complex analysis and nobody else did (it should have been 40 free points, but Kee Young and I were pretty silly during the test).

So how would I have liked this to turn out? Well, barring the screwup on number 2, I'd expect from our current team:

All of the top 15 to solve #1
All of the top 15 to solve #2
Most of the top 15 to solve #3
Some of the top 15 to solve #4
Few of the top 15 to solve #5
Few of the top 15 to solve #6

and I'd want:

All of the top 15 to solve #1
All of the top 15 to solve #2
Most of the top 15 to solve #3
Most of the top 15 to solve #4
Some of the top 15 to solve #5
Few of the top 15 to solve #6

What I wanted actually pretty much happened for problems 1, 2, 5, and 6. Problem 5 is supposed to get a few more solvers than #6, but still not many The problem is the midrange problems. However, as bad as the distribution is, I strongly disagree with making the middle section of the contest easier. The fact is, our A team is not up to par. I'm actually not sure why this is the case. I said in an earlier post that this might be because the class of 2010 made a block that just rose to the surface as a single chunk as the pieces of the team above it disappeared, so as long as nobody else in that block was working, anyone in the block would see their ranking go up for nothing, so why would they work?

Other people (namely Dan) have suggested that the problem is inherent in the ranking system itself. If rankings were kept private, as schools such as Exeter do, then unless one is vastly superior to the rest of the team, there is no magic website to go to that will tell one whether or not he will be on the A team or the B team or on any team at all. TJ has such a magic webpage, and given the fact that these are TJ people, it's inevitable that somebody will notice that no matter what happens, they will be on A team even if they skip the last practice. And then some people might go further and actually skip the practice.

I'm not going to say that Dan's theory doesn't hold water. It very well could. In fact, there are some people who I think would be likely to fall into such mental traps. However, I do have issues with keeping rankings private. The first is somewhat obvious: TJ kids will figure it out anyway. Even if we radically change how scores are calculated, unofficial results will become commonplace. This has been seen in the world of informatics. USACO releases all scores on a month-to-month basis. While their specific parameters are not releasd, our senior computer team keeps its own rankings page which does a simple average and generally correlates well with the camp selections. Additionally, during the International Olympiad in Informatics, results from day 1 appear on Russian sites even before day 2 starts. The International Mathematics Olympiad does it differently, since all grading is done after both days occur and everyone's score except for one problem is made entirely public officially as coordination proceeds. That is much more similar to what we do at math team. The difference is that when 5 of the 6 IMO problem scores are posted, you might know that you definitely made the gold cutoff, but you still have already done problem 6. When 13 of the 14 math team practices are posted, you might know that you definitely made A team, but you're still able to not go to the last practice, and so some people might just do that.

So maybe Dan's idea has some merit, but I think all of this is fundamentally a problem of the idea that results are what matter. Many people take this so far as to believe in the "big fish in a small pond" theory, which says that being valedictorian at a small, no-name school is better than being simply an above average student at a large, prestigious school. By being at TJ, I think most of you have realized that there are some things more important than being valedictorian. But have you realized that there are more important things than being on our A team?

My worry with the block of 2010ers was that they might think to turn TJ into one of the lesser schools so that they could in turn become higher ranked in terms of their own school and put something more impressive on their college application, which would make the admissions officers think that they are better than they actually are, since the TJ name carries a large reputation, and changes in that reputation won't propagate very fast. And with the large block of lazy 2010ers, this was actually possible.

At this point, I think I've broken the block. Our B team contains almost no seniors and the seniors on A team definitely deserve it, since most of them have performed well on at least one of my performance contests. Looking down at the lower spectrum of the rankings, I can see that many of the seniors that I felt were being too lazy to do as well as they were doing are in fact dropping like flies. But most importantly, the seniors are no longer a huge block floating to the surface. And while there might be a huge group of seniors at the top, in all honesty the gap between the A team and the B team is the smallest it's been in years. If the B team improves just a little bit, I am completely confident that they can continue the TJ legacy in the coming years.

However, some people, who will remain nameless here but probably aren't hiding it very much, believe the big fish in a small pond theory to an unacceptable extent. They think that winning the B division of ARML is better than being a random team in A division because they get more prizes. That's a problem.

Some people, when they read this post, probably thought that when I said our A team isn't up to par, I meant that they can't keep up with the other teams. That's not at all what I meant. Actually, I think that perhaps other than AAST and Exeter, we have one of the strongest A teams in the nation. And with the gap between A and B as small as it is, that also goes for the ARML A team. However, we're still not up to par. We're lacking on the mathematical thought process and how to attack a problem that has never been seen before.

I always wondered: how was it possible that some people made our ARML A team and then performed substantially worse at the competition than members of our B team? Obviously something was wrong with the selection process, but what? Well, I believe the answer was that our contests were too formulaic; they could be mastered by just doing math team for a few years and then recognizing the problems. But what happens then when ARML comes up with a new problem type? Those who are good at problem solving but not as fast because they don't have the problem types memorized are on our B team and get the problem, while those who were fast from just problem recognition flounder. That was the fundamental problem of our selection process.

In fact, 99% of all contest problems are very similar to a previous contest problem. So this formulaic method works to a very large extent, and China is able to use it to great success at IMO. And the results of this method are extremely clear: China dominated problems 1-5, while Japan dominated problem 6. Quite simply, had Japan gotten a perfect score on problem 4 and even a single more point on problem 3, China would not have won the IMO. Why did Japan dominate problem 6? Because nobody had ever seen that kind of problem before. Why did China dominate problems 1-5? Because they had all seen those same types of problems before.

I've had several arguments with Richard Peng, who coached the USA IOI team the past few years, about what the correct training method is. He insists that the Chinese method is the correct one because it brings in the most gold medals, while I say that the correct method is to pretend that the Chinese method doesn't work, and instead work on how to solve new problems.

TJ's method tries to emulate the Chinese method of training by providing a thorough overview of all of the types of contest math problems. The first error is that it only covers an overview of the types of problems that we do during eighth period. Those problems that are written by ARML, HMMT, and PUMaC are completely out there, and our eighth period practices don't cover the correct material. The second error is that there simply isn't enough time to provide a thorough covering of all of contest math. We are in school for about 40 weeks per year, of which about 30 are used for math team. If you do 12 problems every week in eighth period, that is only 360 problems. Can 360 problems cover all of contest math? Not at all.

So back to my performance tests. They are my way of pretending that the Chinese method of training doesn't exist. Instead of having the problems be archetypical problems that are likely to appear on a contest, my problems are the kinds of problems that are challenging and "out there". They're meant to have people exercise the thinking process that they use when they don't know how to do a problem, so when they invariably are stuck on a problem at PUMaC or HMMT, they have had practice with dealing with that situation before. In fact, since Arvind is reviewing the performance contests, I'll say that it's not unlikely that HMMT will specifically dodge the types of questions that I have given you. That should not detract from their usefulness if I have done my job right.

Will it be enough to win? In truth, it doesn't matter. Winning is great fun when it happens, but it shouldn't go to your head and you should be focusing on learning first, winning second (if even that). I have made the math team wiki public for that reason: I would rather have our competitors know much of what we know and give us a good contest than have a trophy on my shelf.

AAST

is dense.