I'm not a fan of Poker. I usually play it as a strategy game instead of bluffing, calculate probabilities instead of reading people. One of the mechanics that annoy me in the game is its "capitalism": once you pull ahead you have more options - you are not as scared of going bankrupt as your opponents that don't have the same cash cushion - allowing you to take better calculated risks. In a sense it's a game of snowballing. Taking this advantage to the extreme - a player could repeatedly outbid everyone else once he has the slightest lead (under some rule sets), reducing the game to a farce.
The only mechanism in place to circumvent this strategy is the "all in" rule. An opponent might have 1 last dollar to bid with - but once he is all in, nothing can force him out of the round, no matter how many millions you have. Once he put everything on stake, every last chip he has, he is beyond the rules - for a single moment in time - this round - he is immortal. He is all in.
When you show up on your first day at the start-up accelerator with a sleeping bag - you're all in. You're signaling your peers, employees, investors and competitors that this is your deciding round, you have no plan B. You literally have nowhere else to go. No matter how many millions the competition has.
You're all in.