Level of GM preparation

Hi, 

There's something I've never understood about how GMs prepare. I've seen a couple of instances of chess commentary that alludes to the players' preparation about 15 moves into the game - I've never understood how this is possible.

A striking example is the commentary on the Kramnik-Leko game from 2004. (Agadmator's commentary is here; the game is here.) The commentary mentions a particular position that Kramnik and his team had prepared that's a whole 24 moves into the game. My question is - how on earth is the possible, given the mind-bogglingly vast numbers of ways a game could play out?

I can't imagine that an opponent's opening repertoire is so predictable that you can analyse 24 moves ahead. So how does this happen?

Thanks very much everyone!

Many times a certain course of play is forced, because at the GM level the margin for error is so small, so it becomes increasingly easy to predict moves, since they know that if anything but x is played, white or black is losing, etc.

Here's an example that will probably simultaneously put you at ease and raise more questions

I'll try to answer those too though. Let's use the normal closed Spanish opening

This position after move 9 is sometimes referred to as a "tabia" meaning a standard position. For even amatuer players, a lot of opening prep doesn't even start until this position. For example if black now plays 9...Na5 that's the chigorin, 9...Bb7 is the Zaitsev 9...Nb8 is the Breyer and on and on it goes.

So how can players be sure they will reach this position... well they can't!

On 4 white may capture the knight on c6, that's the Ruy exchange. So black will undoubtedly have looked into that.

On black's move 5 he can take the pawn, this is the open Ruy, so white will have undoubtedly looked into that.

The easy answer is you're right, it's not possible to cover every variation!

I guess then you'd ask why bother? Well, you have to remember these guys prepare for each other year round. It's literally their job. So let's say Kramnik noticed Leko often plays a certain variation all the way to move 20, then of course preparing a few more moves wouldn't be hard.

Or lets say the leading expert on this opening plays a certain way (remember it's their job to prepare these things, so they're always watching other strong players). So again, it may not be as hard as you think to add a few more moves of prep. (And again, just because their prep goes that far doesn't mean it will appear on the board, it often doesn't!)

Again, the easy answer is you're correct!

There are no shortage of stories where a top GM is sitting at the board, trying to remember something he prepared months ago. Why months? Because as you said just because you prepared it doesn't mean your opponent lets you use it! In the above example I used the Spanish which begins 1.e4 e5. Well imagine if you're back and white played 1.d4! haha.

So you'll sometimes hear interviews at top tournaments after the game that are "When we prepared for our match with Anand we came up with many ideas we didn't get to use, and I'm happy I got to use one of them today"

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So again, you might ask why bother.

At the higher levels, yes, your opponents are easier to predict.

But even at lower levels, the soul of the position (so to speak) tends to be the pawn structure. If you're very familiar with a certain structure, and standard piece placements, then no matter what your opponent does you'll never be flying totally blind. You'll have some scaffolding, some framework giving you the general shape and basic idea to work with. And there are only about a dozen or... let's say less than 20 standard middlegame pawn structures.

It's actually mind blowing to hear GMs talk about this sometimes. Svidler in his banter blitz videos often makes remarks like "I know nothing about this opening" or "I haven't studied this for 20 years" but then proceeds to stay in book for 15 moves and quote model GM games along the way i.e. "in the 1970s Larsen had an interesting game in this position that went _______"

So again, their vast general knowledge acts as a framework on which they can build. He says he "knows nothing" because he means it relative to experts on the opening. To us when we say we "know nothing" we probably mean we've never seen the position!

Anyway, that's getting a little off topic.

Hope this gives you a better idea of what's going on.

Absolutely fascinating, llama44. So useful and enlightening. I'll read that back a couple more times at least, but for now, thank you very much again for taking the time to explain that! Really really helpful. 

I am far from being a Grandmaster, but I have regularly played variations going over move 20.

Once I introduced a new move as late as move 42(!), which was found by someone else.