"All-in" doesn't need to be a coin flip, and being patient doesn't need to mean waiting for premium cards. Trapping frequent pushers is much easier than trying to win a flip, preflop. I just noticed that legudus didn't specify between pre- or post-flop shoves. Besides pre-flop all-ins, many players will limp and shove any time they hit a pair. This can happen on the flop, turn, or river. True, it is a freeroll, but a better idea than looking for coin flips might be playing a few more hands and seeing more flops. I see many players shoving low flushes. That would be a good time to call with the nut AXs. Other hands that have this potential might be low connectors, broadways, etc. There are many opportunities to confidently call with an entire stack, other than a coin-flip pre-flop. There are also more optimal ways to build a stack in a freeroll than coin-flips. There aren't enough people taking completely ridiculous lines to justify a coin-flip as a top priority. Against the right players, it can be okay, but it doesn't seem like a necessary strategy, overall.