Here is an actual event (numbers are apx. close)

BB 200,

Short 1 had 4,000

chips
Short 2 has 4,000 chips

Big stack has 12,000 chips

Betting goes in this order

S1 - 200; has AK

S2 - 600; has AT

Big - 600; has Q8 off

S1- all-in;

S2 all-in;

Big calls

(flop QQx .. you know the rest)

It raised for me the question:

At apx what point should a BIG STACK call the short guys - ESPECIALLY when there are 2 of them? In this case he risked 30% of his stack - and he would have been left with a comfortable playable stack had he lost - but by risking 4000 he had the opportunity to win 8000 - for a real big lead.

I think it was a crazy play on his part - he had 2 opponents - twice the chance to lose, way too much to risk (30%) on any 2 cards.

BUT - I wonder if there is a magic number - guideline - when risking chips on any 2 cards in a tourney (apx middle stages of tourney - itm is not too close yet) would make sense.