the things that stick in my mind

He bet on the series, not just one game. So each game the Dodgers lost they came closer to losing the series, which would mean Keitel would lose his bet.

I also found the betting storyline confusing as I'm not American and don't follow their "World" Series.

However the girl showing how she administers oral sex while her friend showed her ass kinda evened things up for me.

SPOILER. Whenever he would lose a bet, instead of paying his bookie what he lost, he would try to win his money back (and then some) by putting twice as much on the next game. When he lost the $60k bet he wanted to bet $120k on the next game instead of paying off the $60k he had lost (which would usually be more like $66k because of the 10% vigorish). His bookmaker (the intermediary guy in the bar) was no longer willing to let him make another bet without paying the $60k he already owed, and told him the name and number of the bookie so he could try to place the bet himself (while warning him the bookie wanted to kill him because he was owed $60k). I don't remember if he was able to place the $120k bet, but at the end he is killed presumably by the bookie's men either because he hadn't paid the $60k he lost, or because he'd won $120k and the bookie didn't want to pay him. There is no significance to the bets being on baseball; it was just a best of 7 game series (first team to win 4 games wins the series); Keitel was convinced the Dodgers were the better team so he saw each loss as a fluke and continued to bet on them.