Why do suit breaks, trump splits and the like not come anywhere near the percentages you see in real life? I charted 80 hands in which there were finesses (no adverse bidding; and yes, I know exactly how the odds change from the bidding and the progress of the play) and 72.4% didn't work, while a 3-2 trump break only happened 52.1% of the time, not closer to 68%.