Racing a horse on a turnaround course
A horse cannot stop and reverse direction as quickly as a man, so Slim won at the turn. In his telling, the win came from the course he chose, not from running faster.
Amarillo Slim in a World Full of Fat People
4 ideas
Never bet on the other man's game
A proposition gambler should only accept or offer wagers in which he already knows he holds the edge. Contests the other person has chosen are, by default, contests where the other person has the edge. Winning comes from choosing and shaping which contest takes place, not from out-performing someone on terms they set.
Equipment handicap that secretly favours the proposer
Slim describes challenging tennis champion Bobby Riggs to table tennis played with frying pans instead of paddles, then practising with a skillet beforehand. The odd equipment looked like it cancelled out Riggs's skill, so Riggs accepted. In fact it moved the contest onto ground only Slim had prepared.
Ask why the bet looks good
Every wager has someone on the other side who believes they are winning. Look at a proposition from the offerer's point of view before accepting: if it seems generous or absurd, the offerer has probably found a condition you haven't. In this view, the mark's pride and the look of an easy win are the tools of the hustle.