odds of getting quads are 407 to 1
Example: You hold TT but the flop misses you completely. What is the likelihood that you will catch a 3rd ten on the turn. Well there are 2 Tens left in the deck, and the deck currently has 47 cards just for arguments sake. 2/47 = .0426 or 4.3%. There is a 4.3% chance you will catch a 3rd ten on the turn. On the river there are now 46 unknown cards, 2/46 = .0434, or 4.3% (just slightly higher believe it or not,alas you dont know if your outs are live most of the time - poker sigh
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odds to hit a set on flop the are 7.5 to 1
turning a percentage to odds example -
20% - 100 minus 20 = 80 80 divided by 20 = 4 20%= 4 to 1
33% - 100 minus 33 = 67 67 divided by 33 = 2.03 33%=2 to 1
I played a home game, not so long ago, and had quad 5"s and quad 2"s inside 10 hands - it happens.
like haworthbantam says it does happen,after a while though you may go many hands without seeing any quads..just variance and probability ..