I agree, teamrichie. If this scum was a lifetime 60% winner, he would have no need to hound people on message boards hoping to sell his picks for a measley $10.
Toutboy, you still don't get it. Your math above is not incorrect, it just isn't relevant to this argument. If people were comparing facts about apples, and one man came and told facts of oranges, he would not be incorrect in his facts about oranges, they would just be irrelevant.
I'm done wasting my time trying to explain this to you. I remembered reading something along these lines somewhere else a while ago, and I found it for you.
Though I disagree with Miller on many things, this is one of the few things that I agree with him on:
(REMEMBER, READ S-L-O-W-L-Y)
There's always an awkward pause when a non-gambler or a beginner asks me, "What percentage of bets do professional bettors win?"
It's a less-than-simple question to answer because it can't be answered simply. That, of course, sounds like a cop-out, but the answer to that question really does demand an explanation.
Many people believe professional-level sports bettors win at least 60% of their bets. It's understandable that people think that, but it's just not true. The fact is, the difference between the percentage of bets won by successful sports bettors and the percentage of bets won by chronic losers is relatively very small.
We'll ignore money line bets here for the sake of clarity, and address only those bets wherein the player risks 11 to win 10; - pointspreads and over/under bets. Against this type of bet, anyone at all can expect to win 50 percent. After all, the only thing required is to flip a coin and pick a side. The bookmakers' profit comes from the difference between what a bettor must risk and what a bettor expects to win. Every time a player wins, the bookmaker withholds slightly more than 9 percent of the winnings ($1 for every $11 risked). Consequently, a bettor winning only half his bets will ultimately go broke.
Professional sports bettors, by comparison, rarely sustain a long term winning percentage higher than 57 or 58 percent, and it's often as low as 55 or 56 percent. People find that hard to believe, and they understandably get even more skeptical when told that, for a genuine professional-level sports bettor, a long term winning expectation of 60% or more is actually too high.
That last paragraph sounds crazy at first, but as crazy as it may seem there is a simple explanation: If a bettor has five bets on a given day, risking $110 to win $100 on each bet, and wins three of them, that's a great winning ratio of 60% and a net profit for the day of 80 dollars. (The bettor wins $300 and loses 220 dollars.) If another bettor has fourteen bets on that same day, risking $110 to win $100 on each one, and wins eight of them, that's a much poorer winning percentage of only 57%, - but almost twice as much profit for the day of 140 dollars. (The bettor wins $800 and loses 660 dollars.)
The second bettor was not necessarily less skilled at picking winners than the first bettor; the second bettor may simply have chosen to apply all his advantages - including those which had less than a 60% chance of winning in the first place. If the ultimate goal is to make money, it is obvious which of those two bettors was more successful. The real goal is, of course, to make money. The measure of success of a sports handicapper is not his percentage of winning bets, but the relative amount of profit he made over any given period of time.
Although there are, indeed, propositions that offer more than a 60% expectation of winning, such propositions are relatively few and far between, and are only a very small part of the overall picture. With the break-even point at about 53%, genuine professional bettors know there is no tenable excuse to pass up propositions offering expectations of higher than, say, 55 percent. A small advantage applied over and over is awesomely effective. Mathematicians will confirm that a profit is more assured from a group of 200 bets with a 55% expectation-per-bet than from a group of 50 bets with a 60% expectation-per-bet. In other words, the more bets placed, the more predictable the outcome. (See our article, Binomial Distribution.)
"The measure of success of a sports handicapper is not his percentage of winning bets, but the relative amount of profit he made over any given period of time."
That, too, is one of the facts of life of which successful bettors must be familiar. It's a basic principle of math: The more bets you are able to place, the more likely it is that your winning percentage will be close to your expectations. A pro bettor must be more concerned with profit than with establishing a great winning percentage, and those two conditions are not always compatible. A real pro applies all his advantages as often as possible, not only the best of his advantages when they occasionally arise.
To illustrate the point, consider casino craps. The house has less than a 51% winning expectation against a passline bet at craps, yet casinos advertise their craps games on signs a hundred feet tall. Casino executives know that if they can get enough players to make enough bets they will end the day with approximately the percentage of profit expected. They also know that the fewer bets placed, the less predictable the percentage of winning bets. Can you imagine a casino wanting to limit the number of times you throw the dice?
The accompanying illustration (below) shows the results of different winning percentages over different numbers of bets. Standard vigorish charges of 4.55 percent are figured into the numbers. (The bookies' net commission is 4.55 percent of all monies risked. See our article, A Crash Course in Vigorish.) Notice in the illustration that winning 55% of 250 bets is more profitable than winning 65% of only 50 bets, - and remember that a profit is more assured - that is, more dependable - because of the higher number of trials.
percent of winning
bets
Total number of bets
50
100
150
200
250
65.0%:
13.3
26.5
39.7
53.0
66.2
62.5%:
10.6
21.2
31.9
42.5
53.1
60.0%:
8
16
24
32
40
57.5%:
5.4
10.7
16.1
21.5
26.9
55.0%:
2.7
5.5
8.2
11
13.7
52.5%:
0.1
0.2
0.4
0.5
0.6
Net number of units profit
Graph shows effect of different win percentages over different numbers of bets. When risking 11 to win 10 it is best to use no more than 2% of your bankroll per bet - (Most pros use about 1 percent) - and 'pull the trigger' whenever you feel you have at least a 55% expectation of winning. Pro bettors tend to have a lot of bets compared to non-professionals. Note that winning 55% of 250 bets is actually more profitable than winning 65% of only 50 bets. More importantly, a bettor is more assured of achieving his expected win percentage over a larger total number of bets, and with more bets and smaller bet sizes, the 'ride' is much smoother, less risky, and more predictable. (Graph assumes all bets are same size.)
Generally speaking, non-professional gamblers go wrong by risking too much of their bankroll on individual bets. They don't spread their risk over enough bets. Professionals use smaller bet sizes in proportion to their bankroll over larger numbers of bets. As a matter of fact, one good way to spot a non-pro is that he invariably has less than a half-dozen bets per week, and he risks more than two or three percent of his bankroll on each bet. (Those sports touts peddling progressive betting schemes such as the "Kelly criterion" or "one-star, two-star, three star" systems aren't professional gamblers at all; they're hucksters selling 900-numbers. Big swings in the size of your bets will send you back to your job at the car wash a lot quicker than bad handicapping.)
If you're a part-timer with a wad of 'mad' money to risk, it may be okay to risk 4 or 5 percent of your bankroll on a single bet, but don't expect to play that way for long. Sooner or later, such mismanagement will annihilate you. To quote from my book, How Professional Gamblers Beat The Pro Football Pointspread, the population of bad handicappers in Tap City is dwarfed by the population of bad money managers. Of those genuine professional-level sports bettors I've known, most would never risk more than two percent of their working bankroll on any single bet, and all of them usually risk much less than that. The general consensus seems to be about one percent.
- J. R. Miller