Saturday, 14 March 2015

Woo, Strike Rate, M/P/H LR and Roulette

While I didn't expect Betslayer to come back with any evidence to back up his assertion that a professional bettor would use goal times, he did return with a comment, or rather a request:

Please do another post on Jonny Grossman he is a massive inspiration (if that means tool).
When a team has played with 4 players called Henry and a goal went in off someones backside, 100% home wins, back at anything over 1.01.

His new 'strategy' of looking at individual teams and their performance in unrelated games after a goal in a time zone is account taken of team strength, league averages or any other betting sense.

In my opinion he is on the pathway to the looney bin.
I think Betslayer means 'loony bin' and from what I read, there are many who are in no doubt that Jonny is already there, but I'm a more charitable fellow and of the opinion that Jonny is just a little different to most of us.

Data is essential, but it has to be relevant. One of Jonny's problems is that he is a slave to the data, trying to find patterns where none exist, and uses data that has no value. The approach Jonny has more in common with astrology than with astronomy, or with Deepak Chopra type woo woo rather than evidence based science. Compiling birth charts might be fun to the practitioner but no one, with the exception perhaps of Bosworth MP David Tredinnick, really believes, with good reason, that they have any merit. I'm an Aries, so I should know!
Astrology is a useful diagnostic tool enabling us to see strengths and weaknesses via the birth chart.
“And, yes, I have helped fellow MPs. I do foresee that one day astrology will have a role to play in healthcare.”
Mr Tredinnick, 65, added: “Astrology offers self-understanding to people. People who oppose what I say are usually bullies who have never studied astrology.
“Astrology was until modern times part of the tradition of medicine ... People such as Professor Brian Cox, who called astrology ‘rubbish’, have simply not studied the subject.
“The BBC is quite dismissive of astrology and seeks to promote the science perspective and seems always keen to broadcast criticisms of astrology.”
Tredinnick claimed £755 in expenses for software that used astrology to diagnose medical conditions, and rightly had to repay this amount.

Back to Jonny, and it may be fascinating to him that a Conference South team scoring first between the 11th and 20th minute goes on to win the match 73% of the time, but it has no practical value. It's as useful as knowing that Jupiter has entered Leo and will transit until the 30th.

There's no liquidity for one thing, which means there's almost zero chance of finding value, and who wants to spend close to two hours in front of a screen chasing pennies? For most of us there's a considerable opportunity cost to be considered when betting, but apparently not for all of us.

The topic of how useful is the Strike Rate from a couple of posts ago, triggered a mini conversation between Tage and Marty.

Some players use strike rate (SR) to determine a system's betting bank. SR determines Maximum Losing Run (MLR). For SR = 50% is MLR = 10 and for SR = 25% MLR = 24
When MLR is known betting bank can be calculated.
For a DNB system, it therefore matters how SR is calculated.

Let me add that I think there are better methods to determine betting banks.
Marty asked:
How can MLR be calculated without knowing the odds bet at?
If I have a SR of 50% but bet at 10 my MLR is going to be a lot longer than if I bet at 1.5
Your SR would probably be higher for bets at 1.5 than for bets at 10.
But if you actually have SR=50% for both types your MLR would be the same.
To save Cassini for some work I should add that my numbers are only examples. Don’t take them too literally. It’s the issue I want to focus on, not the math.
Oh, so MLR is the NUMBER of matches you can lose in a row then (I guess assuming some worst case probability).

Seems equally as dubious as SR then.
The idea of a betting bank to me is conceptual as I mentioned here and of limited use.

In practice, bettors will call it a day on a system when they hit a poor run, and save what is left of their bank for another system. They may also simply start again with another bank if they are of the opinion that they just hit a bad run of luck. Either action renders a betting bank pointless. The discipline required to work to a bank simply isn't there for many bettors.

The longer you play a system for, the greater the probability that you will hit a long losing run. Tage makes it clear that his numbers are examples, but the MLR can't be calculated without knowing the number of bets to be made, and even then, the name MLR is misleading.

If your Strike Rate is 50%, then over 100 bets, you are likely (a greater than 0.5 probability) to hit 6 consecutive losers, but in theory, the MLR would be 100 since you COULD lose all 100. So to call it a Maximum is, in my opinion, wrong. PLR for Probable Losing Run is my preference, or HLR (Historical Losing Run) for record keeping purposes.

Just to illustrate how the PLR increases with trials, over 1,000 bets you are likely to hit a losing run of 9, and over 10,000, a run of 12.

For a 25% Strike Rate, the probable losing run over 100 bets is 12, for 1,000 it is 20, and 10,000 it is 28.

Discipline and handling losing runs is one of the biggest challenges bettors face and while many of us probably spent hours of our youth poring over sequences and back-fitting staking systems, not so many of us have been able to stick with one in practice.

I write about a gullible young Cassini and his Roulette adventures a couple of years back. On the off-chance you missed that post, and shame on you if you did, the relevant portion is this:
It was in the late 70s when, anxious to try out one such brilliant system, I wrangled an invitation through a colleague to an illegal Chinese run gambling den somewhere close to Piccadilly Circus. I was a little surprised that not only did they let me record the outcomes of spins and take notes, but they provided the pencil and cards for it. This was all too easy I thought.

I didn't win, and had to go in to work next day.
My partner in crime that night stopped coming in to work soon after. He was working the graveyard shift, and thought it would be amusing to call the department manager up at 3am and report a problem with the computer system. In those days such a call necessitated getting dressed and driving in to the office, and he was none too pleased to arrive at the office and find my erstwhile friend somewhat the worse for wear and slurring "April Fool" to him. I never saw him again. Perhaps he found the Roulette Holy Grail?

1 comment:

Betslayer said...

I don't need to back it up, I'm a professional bettor and I use goal times.

I know of at least two others who use it as part of their analysis.

BUT the key is, its not the soft data that Jonny uses such as in the last 10 Liverpool games with a goal in 0-20 10/10 BTTS etc etc Thats no better than formlabs or other bookmaker backed data suppliers.