does anybody else try to come up with % calls for games?

[EXTRAPOLATER]

I've been doing so for years. I had a great system going for NFL football--which I might try to use again this coming season. I'm currently using a system which gives me percents on baseball games. Results have been mixed, but I'd say that I'm on the right track.

I think that the best way to assess any lines is to compare them to a reasonable percent call, but I believe that most 'cappers simply look for winners (which we all do) without actually trying to get a gauge on the probability for a game. I could be wrong, but my experience of 7 years at this site (and others) hasn't shown me anybody else trying to come up with concrete probabilities.

If one has a game 'capped at 60%, say, then you can quickly assess a line of, say, -110 and determine that you have a "value indicator" (as I call it) of +7 (the break-even mark for -110's is 53%).

Somebody out there must have also thought of this approach. I can't imagine it otherwise.


If you've used this approach then please let me know.
If nobody uses such a strategy then I guess that opens the door for my book project.

If you think that such an approach is fruitless, or even difficult, then chime in please.

Hopefully this is the appropriate forum for such a discussion.

 

[EXTRAPOLATER]

I'm going to keep bumping, for a while, to hopefully get a response.

Maybe I'd have better luck in the 'capping forums, but I'll keep this one alive for now.

Anybody who lays -105 on the coin-toss for the Superbowl need not reply.

Those that are interested in finding true value will hopefully respond.

Can't hurt to ask.

:SIB

 

[IE]

Handicapping & Baseball Math

How are ERA and other statistics computed? How often should a team playing say .600 ball beat a team playing .400 ball? Can a game be "modeled" with available stats? With this season not old enough for trends articles, we take a short look at baseball numbers this week.

Earned run average is figured by dividing earned runs (runs not scored on errors) by innings pitched and multiplying by nine. The result is the average earned runs given up by the pitcher in a nine-inning game. ERA developed during the long period when there were many complete games pitched. There are many arguments, qualms and questions about ERA, but its use persists, and will into the forseeable future. It is a simple measure of pitching effectiveness that is widely understood and easy to compute.

Starters ERA are higher than relief pitchers, mainly because runners on base when a starter leaves the game are charged to him if they score off a relief pitcher. A fairer way might be to charge the pitcher who puts a runner on base with 1/2 earned run and the one who lets him score with 1/2 run.

Another difficulty with ERA is how the short awful outing balloons the number. Consider this sequence of starts:

IP ER "game ERA"

6 1 1.50

5 0 0.00

7 2 2.57

1 7 63.00

The ERA for this pitcher is 4.74 after four starts. Yet he is clearly a better pitcher than that, with three good games out of four. His team shuld be 3-1 in his starts. If a limit of 9.00 is placed on the ?game ERA" (which is the ERA for only that game), and the games are averaged, His ERA become 3.26, which seems to more accurately describe this pitcher?s record. We could publish this way, but it would suffer from lack of understanding and acceptance and be a bit more difficult to compute.

Some readers do a modeling with our numbers. If a pitcher is throwing 6.33 innings per game, giving 3.5 runs, they take that and the bullpen ERA and produce a model of his start, sometimes adjusting for home or road or other factors, then adding in a factor for the bullpen and a factor for unearned runs, to produce and expected yield of runs, then compare it to the opponent?s run scoring average. This is just a skeleton for a model, which could be modified any way the handicapper wants.

Other handicappers do no such math procedures. they look at ERA and determine that 3.21, 3.36 and 3.67 are fairly good numbers, and that 4.95, 5.32 and 6.09 and not very good and draw conclusions. Some divide hurlers into two main categories, above-average and below-average, with extremely good or bad pitchers in smaller categories, respectively not to be bet against, or bet on, until their performance changes.

Log5 is method developed to quantify the winning chances of one team v. another. Wins, runs or win percentages can be used, just so a comparable loss, runs yielded or losing percentage is used. Using wins:

win% Team A v. Team B = winsA x lossesB

divided by

(winsA x lossesB)+(lossesA x winsB)

So if New York were 88-59 and Montreal were 70-72

if would be 88*72/(88*72)+(59*70) = 6336/10466 = .605

New York would win about 60% of the time. Translating that percentage into odds, New York should be about a -1.55 favorite in the game.

To get odds as percentage, divide the favorite odds by the odds + 1.00, so for a -1.55 favorite use 1.55 divided by 2.55 = .607 A -3.50 favorite becomes .778, a -1.25 favorite becomes .556, etc.

 

[IE]

what is true value???

 

[UGA12]

Think all your questions would be answered in the baseball forum. I know there are guys around who at least have a variation of this. Finding a percentage relies on factors that one fixes a value to. Those factors and/or values are relative to the individual and there are literally thousands you could factor in. I know you know all of this, just trying to say I think this is what most people do just not the exact same way or with the same factors/values. There are people much smarter than me on this subject that will help you out in the baseball forum, GL

 

[IE]

didn't notice the edit for football, disregard...sorry

but again i ask what is the definition of true value to you?

 

[EXTRAPOLATER]

Interesting post, IE.
I'll have to read it over, again, tomorrow, after I've had some sleep.

As for the definition of "value", well...that's a good question.
Nevermind the "true" part--let's stick with VALUE.

I agree with standard definitions, here:

--An amount, as of goods, services, or money, considered to be a fair and suitable equivalent for something else; a fair price or return.
--Monetary or material worth: the fluctuating value of gold and silver.
--Worth in usefulness or importance to the possessor; utility or merit: the value of an education.


Value FOR A WAGER, which is of utmost importance to us here, must ALSO be "considered to be fair and suitable". The example I used earlier, of laying juice for a coin-toss, would have no (or negative) value as a SUITABLE line for a coin-toss would have to be +100 (or better). At +100 we'd be getting a "fair price" but the measure of value would be negligable, thus limiting "usefullness or importance".

I consider there to be value on a wager if the probability of the outcome is GREATER than the break-even mark for the available line. At +100 my break-even mark is 50% so anything above a 50% probability will give me "value", or a measure of "usefullness". I'd say there is clearly more value on a 60% probability, at +100, then there is on a 55% probability, at the same +100.

I could go on about this stuff forever here, IE, and I'm not sure if you're just trying to yank my chain or what; probably not...it's just an intriguing question.

Take the example of a blackjack player. She knows that there is going to be greater value on a wager when the card count is high, and she will risk more in these situations as the probability of winning will be higher. The higher the probability of winning, the greater the value, but that value will be determined by the price. If "the amount of goods or services" (the probability) offered is considered fair then one has value. The FAIRER it is the greater the value, if that makes sense.

If that doesn't make sense then I'll need to sleep on it and tackle the question again tomorrow.

The formula uou suggested that some people use is interesting; I've tried such a simple approach in handicapping hockey games, which I find very difficult to handicap.

Looking back at my post I don't see that I used the phrase "true value." Regardless, your use of true would have to signify "definitive" or "absolute" value. I imagine that such could only be determined if we have an accurate gauge on the probability. e.g. on a coin-toss we should be relatively secure in assessing the probability at 50%, so a payout that would provide "value" (be a fair exchange) would, in fact, provide "true value" as we've got a definitive gauge on the probability.

This probably needs to be edited but I'll have to leave these ramblings as is, for now. I appreciate the input and, to tell you the truth, any criticism or skepticism that comes forth will likely do me much more good than any kudos that might come forth.

Fire away.

I'll be back in the ring, again, tomorrow.

GL always

:SIB

 

[EXTRAPOLATER]

One more thing...

As for "an accurate gauge on the probability", which I argued must be had for their to be "true" value, well...that is where my system for baseball has a big question mark. I can really only determine the accuracy of the calls by keeping statistics on each call to see what % of them come in. I've even thought about trying to come up with a probability modifier, for example to have a call at 60% +/- 5%. An error modifier (or what the hell do they call those?!?) would make sense as my numbers cannot really be determined to be accurate without something to back them up (a year's worth of stats?...might help, but still wouldn't make my probabilities CONCRETE, or "accurate"). I haven't forked around with any such silly modifiers as it should be clear that there is an error range on any call, and my system is only liking plays if there is a "value indicator" (as I call it) of at least +5...meaning that I should hopefully escape that error range.

I don't know if the above helps or hurts.

I'll leave well enough alone, for now, and check back in tomorrow (today).

Thanks for those already,
and thanks in advance
for any responses.

Mike

 

[Terryray]

I've fooled around with this sort of statistical analysis in baseball. Gonna start it up again soon (season has gone on long enough now to get some good trend
statistics).

Almost all the pros do it by creating their own line, then if the difference between their "true line" and the real one is great enough--they make a bet.

the standard start to creating a line is Clay Davenport's tweaking of Bill James Pythagoream. You then input the expected win % in a formula to determine the Return on Investment--that ROI is the measure of your value.

for example, I figger Angels tonight at -205. Your expected return, for each $100 bet, is (100/205)+100=$148. So that's $48 profit after you subtract the $100 you used to make the bet. The actual line is -165. Expected return on that is $168. The difference is 168-148=20. You then divide the difference by your expected return (20/148)=13.51%. This is your ROI.

you really want a ROI greater than 10%, depending on how strong your line has been proven (over MANY seasons! One or two seasons means little).

so Angels is a strong pick tonight, part of that strength is the tweaks I put in my line--Angels' starter I expect to be better than normal, as he is
in a "bounce-back" situation after a poor start, and Angels should play harder to avoid sweep. You add on as many value tweaks as you have time. Umpires, for example..


Murray's book "Betting Baseball" covers all this, and also read the superb baseball details in Bob McCune's books--all available at Gambler's Book Shop in LV as Hooks mentioned-- those would be where I'd point anyone to start on this.


all this work and maybe someday I can get as good as gsp, or RexBudler or all the others posting here!

 

[KotysDad]

This is a very interesting topic, whether for baseball or any sport. I'll throw in my 2 cents...if its worth even that. haha

I cant imagine the number of factors you'd have to take into account to come up with an accurate assessment of the team's probability to win a game.

I find baseball the most fun sport to handicapp with all the statistics you can find on each player and team.

I like IE's ERA example of how misleading that stat can be, along with wins and losses. I dont look at either to be honest, but will share my method of analysis just as an FYI.

I only handicapp starting pitchers due to time constraints. I use a relatively simple formula to come up with a raw score on a pitcher's performance based on stats you find in the everyday boxscore. From that raw score I'll "tweek" it slightly based on certain variables like ballparks or weather, etc....but I can in no way quantify my method of tweeking as it is purely by gut instinct. Then I take that net score and assign it an elementary value of A, B, C, D or F depending on what range the score falls into.

In IE's example, that pitcher would have scores somewhere around A, A, A, F in my book.

I'll do this for all starters (AL only) and keep a log book each day to analyze matchups. This takes up about 20 minutes of my time each day.

Then I'll look for matchups that are "favorable" based on recent outings and the current line...usually only look at the previous 3-4 starts. As an example, say....

Kazmir (TB) +180 vs
Mussina (NY) -220

In my stats, Kazmir might have previous scores of B, C, A and B.....while Mussina might have previous scores of C, C, D, and B. In this case, I would gladly take a chance on Kazmir getting +180 considering his last 4 starts were "quality" starts, regardless of what his ERA or W/L might look like. Even if Mussina had more impressive starts, I might still take Kaz at +180 figuring he is pitching too "good" to not take a chance on +180 - irregardless of who is opposing him.

It's one method (I am sure there are hundreds) I use to try to assess some value....how much? probably not much but I feel for 20 minutes of time a day I have a slightly better chance than a monkey throwing darts at a board. One thing I like about it is I generally am betting on the dogs....some might call barking dogs.

I havent kept good track of my results as I only do this for fun, but it has made me a small profit over the last couple years.

I wish I could find a similar stat to use for basketball and football. For now my basketball and football system is comprised simply of looking at the lines and looking to see what side looks "ridiculously easy" then taking the other team. I guess I consider myself a square when it comes to football and hoops, but with baseball there are so many stats at your disposal, its really worth investing a few minutes each day trying to use them.

 

[abc]

I dont.. although I am pretty strong in math ( more so than english at least). I just know the odds of me picking a winner in golf at either +115 or -200 is about 65% . :SIB

Occasionally there will be a line like Angel Cabrera to make the cut at -150 ( at the open) i knew he was 7 for 7 making cuts so yes I saw value in that line..

 

[EXTRAPOLATER]

Thanks a lot for the responses.

This is a bit of an obsession for me, this season, as I'm really giving it a solid go with a system that I've been working on for years.

Terryray, I really appreciate the book recommendation. That's sounds like a really good place for me to start, as far as scoping out available books.

I use a slightly different method to calculate ROI but the results are the same. If you've seen any of my baseball posts then you should have an idea of how I try to assess value. I'm currently using a pair of methods to assess value, but I'm relying on the probabilities that my system calls.

Results have been acceptable.
Unfortunately, I'm trying to be a bit of a perfectionist in my methods, or at least to get as close as I can to reality. Losses become a little harder to bear when you're (I'm) taking things too seriously.

I'll be enjoying the All-Star break.
It's coming at an ideal time.