[donjuan]

I would advise taking a statistics class (or thoroughly reading a stats textbook) and understanding how to apply concepts presented in said class/book to gambling before even attempting to write a book on sports betting. I realize your intention is good, but all you are doing here is spreading mis-information. The following may seem harsh, but I feel it's the best way to get the point across:

The average professional sports bettor aims to have a winning percentage of 57% per 500 wagers.

Is this number plucked out of thin air? Firstly, you probably want to state the odds you are getting on such wagers. If you were betting exclusively -200 wagers, then 57% would be awful. If you were betting +200 exclusively while hitting 57% you would be doing absurdly well. Assuming you are talking about -110 ATS wagers, 57% is definitely on the high side (for major American sports with high limits). Think about why this is, assuming you are attempting to maximize profit and not just maximize winning percentage.

The best professional gamblers realize that their bankroll will only exceed its former peak 5% of the time they spend wagering.

Are you talking about being up at the end of each day here? If so, that is patently wrong, assuming you aren't making something like one +10000 bet every day.

When you are altering your wager size by any amount you will increase your break even percentage from 52.38%. If you choose to play your wagers on a 1-10 unit rating scale your break even percentage jumps above 55%. After time the only wagers that will make you a winner are the larger ones, so why even bother betting the smaller plays?

Your breakeven percentage isn't determined by how much you bet, but rather by the odds. To find the breakeven percentage on - MLs the formula would be -x/(100-x). For + MLs, 100/(x+100). However, the amount you should bet should vary based on your percentage.

We have all heard the saying, “When your hot, your hot!” In gambling you should never use that approach to determine your bet size. Going 6-0 on Tuesday has no effect on what you will do on Wednesday and in turn should have no effect on the amount you wager. This same concept applies to a devastating cold streak. If you have not been able to pick a winner in 10 plays, you should not drop your wager size down. If you knew you were on a hot streak and would win your next wager, why not lay down ten times your normal wager? If you knew you were on a cold streak and would lose your next wager, why risk anything at all?

The gist of this is fine in that streaks are meaningless. However, saying that you should not alter your bet size after winning or losing 10 in a row is wrong. It is not wrong because of being "hot" or anything silly like that, but rather because your bankroll has changed. Your bets should always be based on a percentage of your bankroll so after 10 losses in a row your bet size should have diminished.