Here's another trick it's worth knowing about. It's not one I've ever managed to pull but I've fallen for it a few times and lately I've managed to spot it and avoid it. Sadly I didn't learn the trick by analyzing what was going on in my games rather I spotted it when watching friends fall for it.
It's funny how your rating drops 200 points when you sit down to play and rises 200 points when you stand up and go and watch someone else's game ;-)
The setup: a 400+ rating difference and the game is heading for a draw! In fact it is dead drawn. So dead drawn that as long as the weaker player steadfastly sticks to his ambition to draw it is going to be a draw.
With such a large rating difference the stronger player really can't afford a draw. The tactical draw offer isn't likely to work. The stronger player can't accept the draw. So, what is he going to do? What he needs is a sucker punch.
My club runs a regular Monday night 9 round Swiss standard FIDE rated competition with large enough prizes that 3 or 4 grandmasters will usually turn up to hoover up the prize money. Nevertheless for us low life players we occasionally get the chance for a shot at glory against one of these chess demi-gods. Usually it ends quickly and ignominiously, fortunately before any of our friends' games have finished so they don't witness our humiliation.
But once or twice a year you'll get up from the finish of your game, look up to see how Joe is getting on against the GM and, lo and behold! the pair of them are still sitting at the table. Maybe he's in there with a chance?
About a year or so ago I got up in that situation and saw that a regular sparring partner was in that exact position. Not only that, the game looked to be a dead draw. 2 rooks and a few pawns each, a couple of weaknesses each, no real chance to mount a serious attack against any of the weaknesses. All Joe had to do was hold his nerve and glory (at least from his peers) was guaranteed.
They must have just recently reached the position because Joe made the regulation draw offer and without blinking or hesitating the GM made his move and pressed his clock. What followed was some fairly meaningless looking maneuvering by the GM. Joe didn't move from his bunker. Then the GM made a weak looking move. Joe could move one of his rooks into the GM's position and make a couple of threats. They were easy enough to parry but there was no danger. If the threats didn't come off Joe could always move his rook back into the bunker.
The GM parried the threats but did so clumsily. Joe could, if he wanted penetrate even deeper and it looked like he could win a pawn. However with my extra 200 ratings courtesy of supporting my weight on my feet rather than backside I could see that once that pawn was won the rook would take a while to get back into play and in the meantime his remaining bunkered rook and king wouldn't be able to handle the threats from the GM's two rooks and king.
"Don't do it!" I wanted to shout, but it wouldn't have made any difference, apart from getting me thrown out. Joe was seeing through red mist, he thought he'd won the lottery. He wasn't just going to draw with the GM, he was going to win! The GM landed his sucker punch and Joe was the sucker.
Losing a dead drawn game to one of your peers hurts a bit but doing so against a much, much stronger really hurts. It hurts so much that the pain spreads to the spectators. Everybody loves an underdog and an upset and you nearly did it.
Why did it happen? If you're like me your whole game plan was aimed at the draw. Luck was on your side and you cooly managed to execute 98% of the plan. You did the hard work but at the last moment you let emotion overwhelm your rational side and fell for a cheap trick from the GM.
Remember the GM has earned his title. If he appears to do something stupid just remember who you are playing. You have two choices. The first is to trust your opponent and stick to your plan blindly. A bird in the hand and all that. Opportunities like that are scarce. The second option is to suspect that despite all the evidence your opponent has made a mistake. After all, he played badly enough to let you get the drawn position in the first place. Maybe it just isn't his day?
If you are going to do that you better have plenty of time on your clock and you better put in your maximum effort in analyzing the consequences.
If you massively outrate your opponent and you end up in very drawn position what do you do? You give him hope of even greater glory, a win! You lure him gradually down a path of getting more and more out of position with the promise of material or positional gain. Only you've seen just a little bit further. The alluring path leads to his doom.
This is an old trick and is standard procedure against computers, usually with prepared variations. Often prepared with the help of computers ;-) Lure the computer with a sacrifice who's payoff is outside the computer's calculation range and it will blindly fall into the trap.