After watching The Big Show and IM Rench's simuls often, I would say usually even when the player has a better position than the IM usually they blow it because most lower rated players don't have the endgame technique to convert a win against resourceful competition.
If you were be able to play against a GM in simul, how would you prepare?
Sort:
There is no preparation !! lol
Halloween Gambit, if it would happened around 1st... otherwise it depense what GM
prepare to resign but play the most favorite opening.
I played 4 simuls in my life:
1st: (against an IM): played a KID. He played a line I had never seen before (h3 system IIRC). Got a very bad position out of the opening and I was getting ready psychologically to suffer a quick and painful death. And then .. he blundered an exchange. Thinking back on it my position was probably winning. He had the bishop pair though and that day I learned what a powerful weapon it can be in the hands of an experienced player. He very slowly continued to improve his position while I was clueless as to what to do. I lost of course.
2nd (GM): Got crushed. Had a losing position after 15 moves.
3rd (GM): Got crushed in the same fashion
4th (GM, at the time he was an up and coming player around 2500 now a 2700 super GM which makes the memory even more painful now). He had a pretty strong attack on my king and I don't think I would have survived very long. And then ... he blundered a full piece. Considering the attack I wasn't even sure if it was a sacrifice but he confirmed it was just a blunder after the game. I played passively and lost quite quickly.
So my advice:
- Your best chance is to get into a tactical struggle. Ok most of the times you'll be the one blundering the piece but the last thing you want is to get into a "simple" position. These guys play endings too well.
- Play actively, look for counter-chances.
I'd just prepare by hiding a few extra pieces up my sleeves.
I'd do monkey bar situps, let the blood rush to my head, and annotate lines upside down with an astronaut pen.
You will undoubtedly lose, so why to bother?