LR Question 25 Explanation
QUESTION TEXT: One way to compare chess-playing programs is to…
QUESTION TYPE: Most Strongly Supported
FACTS:
- If two computers use the same chess program and have a fixed time limit per move, the faster computer has a better chance of winning.
- This is because the faster computer can calculate more moves within the time limit.
ANALYSIS: You have to be careful with this. The author is not saying that speed always wins. They’re saying that when other things are equal, speed helps to win.
Remember, the two computers are using the same chess program. It’s possible that a different program would be worse, even if it was on an infinitely fast computer. For example, I could write a chess program where my King charges solo towards the other side every time. That program would lose every game, no matter how fast the computer was.
___________
- This says “different chess playing program”, so it’s wrong. The stimulus talked about the same chess playing program. A chess playing program might be able to examine many moves and yet have a bad strategy.
- The argument never said what makes a computer compatible with a chess playing program. Maybe speed is a factor. Some computers are too slow to run some software.
- CORRECT. This is supported by the argument. In the experiment, the researchers held every factor equal except the number of moves analyzed per turn. And they said more moves analyzed per turn improved the odds of victory.
- Same as A. The stimulus was talking about two computers running the same program. This talks about different programs.
A certain program might be really inefficient and therefore slow at analyzing moves, even on a fast computer. - This does say the same program, which is good. But, it doesn’t say how much more time the computer has. If it gets 10% more time, but the other computer is 200% faster, then the faster computer will still analyze more moves and have higher odds of victory.
More Resources for Most Strongly Supported Questions
- Intro Course lesson: This intro course lesson covers Most Strongly Supported questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers most strongly supported questions.
I eliminated answer choice C on the basis that “moves” is not equivalent to “possible moves” from the stimulus. I thought this distinction was relevant as spending time to consider all moves, including nonlegal moves as opposed to “possible moves,” would not necessarily increase the chance of winning, especially considering the time constraints. Distilled, it is not necessarily the case that as the number of total moves examined increases the number of possible moves examined increases. Hence, by my view, answer choice C is not necessarily generalizable.
The LSAT expects you to make reasonable assumption. The reasonable assumption here is that a chess-playing program will be programmed to only allow legal moves, not nonlegal ones. If a computer is programmed to play a game, it doesn’t really make sense for that program to include considering moves that go against the rules. After all, why would you program a computer to play a game and then not ensure it follows the rules of that game?
As for “possible moves” vs “moves”, they’re referring to the same thing. The former is just a more elaborate version of the latter. Again, in C, you shouldn’t assume that just because it says “moves” and not “possible moves” or “legal moves”, that the moves in C include nonlegal ones. We’re still operating under the same context, which is a computer algorithm programmed to play a game, and the only reasonable assumption there is that it is programmed to know the rules of the game it’s playing.
Hope that helps! Let me know if you have further questions.
I got trapped first by answer A and struggled a lot to justify why it’s wrong. The reason is because the first sentence made answer (A) especially tempting. Here’s though why I think it can’t justify it:
It says “one way to compare chess-playing programs”, it doesn’t necessarily mean the only way (could be the design of the software etc.). If I say “one way to compare cars is to compare their maximum speed”, it doesn’t mean that the fastest cars are always gonna win the race (there are also factors such as stability, acceleration etc.).
I think you’re giving A too much credit. Imagine one program was very fast, but it’s entirely programming was: move a pawn forward, or failing that move the king forward.
It could move very quickly and would quickly lose. Speed is important, but when you have different programs you also can have different strategies. And a bad strategy executed quickly will absolutely make you lose in chess.
Note: This is an old comment but I wanted to clarify the point.