See the top rated post in this thread. Click here

Page 1 of 2 12 LastLast
Results 1 to 13 of 26

Thread: Sports betting related math question

  1. #1


    Did you find this post helpful? Yes | No

    Sports betting related math question

    If you’ll allow another sports betting post. Some of you math nerds love this stuff though . Promo offers a “risk free” 1st score basketball bet. You bet $25 and receive it back in free bets if it loses. Most of these odds start at +400 or +500 for the favorite and step up from there. I work through 5 accounts. So, question is how can I figure the odds that one of the 5 favorites is the one who makes the 1st basket? For simplicity sake, let’s assume it’s +500, +600, +700, etc. Thanks

  2. #2


    Did you find this post helpful? Yes | No
    What odds you get when the bet wins has nothing to do with the question you're asking. They're separate concepts. For NONE of the five favorites to make the first basket, is about one chance in 32. No matter which is the better team, making the first basket is somewhat of a tossup. So, in five games, at LEAST one of the five favorites will make a first basket 96.9% of the time.

    Don

  3. #3


    Did you find this post helpful? Yes | No
    Quote Originally Posted by DSchles View Post
    What odds you get when the bet wins has nothing to do with the question you're asking. They're separate concepts. For NONE of the five favorites to make the first basket, is about one chance in 32. No matter which is the better team, making the first basket is somewhat of a tossup. So, in five games, at LEAST one of the five favorites will make a first basket 96.9% of the time.

    Don
    Sorry, apparently I did a terrible job articulating what I was asking. What I would be doing would be betting on the same game, across 5 accounts. In each account, I would pick a different one of the top 5 favorites to make the first basket. So, I’m trying to find out how to calculate the odds that one of those 5 players would score first. What are the odds I win one of those bets? If I knew those odds, in conjunction with the $25 free bet return on the losing bets, I believe I could figure out whether or not it was a positive EV situation. Thanks

  4. #4


    Did you find this post helpful? Yes | No
    Quote Originally Posted by Old new guy View Post
    Sorry, apparently I did a terrible job articulating what I was asking. What I would be doing would be betting on the same game, across 5 accounts. In each account, I would pick a different one of the top 5 favorites to make the first basket. So, I’m trying to find out how to calculate the odds that one of those 5 players would score first. What are the odds I win one of those bets? If I knew those odds, in conjunction with the $25 free bet return on the losing bets, I believe I could figure out whether or not it was a positive EV situation. Thanks
    Oh, so you're betting on individual players to score the first basket, and you'd like to know the odds that one wins, assuming they're ALL +500, +600, or +700? Or, do you assume different odds for each of the five bets? Answer the above question, and I'll let you know. (It would be much easier if the odds stay the same for all five players, regardless if they're all +500, +600, or whatever.)

  5. #5


    Did you find this post helpful? Yes | No
    If what you ask is the implied probability for the different odds, that is easiest calculated by converting the odds to European decimal odds, and divide those odds by one. For +400 the decimal odds are 5 and the implied odds are 1/5. For +500 the decimal odds are 6 and the implied odds are 1/6 and so forth. Hope this helps. The true probability is of course lower than this, because of the wig.
    Last edited by mike235; 11-10-2021 at 06:39 PM.

  6. #6


    Did you find this post helpful? Yes | No
    Quote Originally Posted by DSchles View Post
    Oh, so you're betting on individual players to score the first basket, and you'd like to know the odds that one wins, assuming they're ALL +500, +600, or +700? Or, do you assume different odds for each of the five bets? Answer the above question, and I'll let you know. (It would be much easier if the odds stay the same for all five players, regardless if they're all +500, +600, or whatever.)
    Yes..the bets are on individual players to score the first basket of the game. The odds are all different, as you would expect some players to be more likely than others to score first. An example of the top five for tonight’s GS/Minn game is Curry +450, Towns +550, Russell +600, Wiggins +600, Edwards +650. So, I would pick each one of these guys in each of my 5 accounts. Any one of them winning covers my losses in the other 4. Plus, I get 4 $25 free bets. So, that is positive AV for sure. But..one of them has to win. So, I would like to know the odds that any one of them would win, given these odds. If you’d like to teach me to fish, how could I figure it out for any example of odds? (Assuming the math is a few steps below your level . ) Thanks

  7. #7
    Senior Member
    Join Date
    Sep 2013
    Location
    yep...want my phone #, too?
    Posts
    949


    Did you find this post helpful? Yes | No
    So you want to know the odds of one of the top 5 players in a basketball game scoring the first basket?....hmmmm....assuming that they all start the game and there are 10 players total, I say 50%

  8. #8


    1 out of 1 members found this post helpful. Did you find this post helpful? Yes | No
    Quote Originally Posted by Sharky View Post
    So you want to know the odds of one of the top 5 players in a basketball game scoring the first basket?....hmmmm....assuming that they all start the game and there are 10 players total, I say 50%
    Also: "If you’d like to teach me to fish, how could I figure it out for any example of odds? (Assuming the math is a few steps below your level . ) Thanks"

    Well, it's not exactly 50% just because you have five of the 10 starters, because you may have the best five, the worst five, or the middle five. You can't just say you have half the players, so it's 50%. With the stated odds, you have to calculate that none of the five will win, and then the probability that one of them will win is 100% minus that calculated value. Actually, you have to invoke that concept twice.

    So, first you change each of the odds to win to fractions: 2/11, 2/13, 1/7, 1/7, and 2/15. Those are the chances of each winning. So the chances that each of them loses are: 9/11, 11/13, 6/7, 6/7, and 13/15. The chance of all five losing is the product of those fractions: 9/11 x 11/13 x 6/7 x 6/7 x 13/15 = 0.441. So, the probability that one of them wins is 100% - 44.1% = 55.9%.

    If you bet $25 five times (total of $125), your e.v. is 0.559 x $125 = $69.88. In addition, you get four free $25 bets, or $100 in free bets. It matters, of course, how you bet that, but if you were to make four straight point-spread bets at -110 each, that e.v. would be an additional 100/210 x $100 = $47.62. Together, your total e.v. is $117.50. Sadly, you're $7.50 short of your $125 outlay, so you lose 6%.

    Did I teach you how to fish?

    Don
    Last edited by DSchles; 11-11-2021 at 08:56 AM.

  9. #9


    Did you find this post helpful? Yes | No
    Quote Originally Posted by DSchles View Post
    Also: "If you’d like to teach me to fish, how could I figure it out for any example of odds? (Assuming the math is a few steps below your level . ) Thanks"

    Well, it's not exactly 50% just because you have five of the 10 starters, because you may have the best five, the worst five, or the middle five. You can't just say you have half the players, so it's 50%. With the stated odds, you have to calculate that none of the five will win, and then the probability that one of them will win is 100% minus that calculated value. Actually, you have to invoke that concept twice.

    So, first you change each of the odds to win to fractions: 2/11, 2/13, 1/7, 1/7, and 2/15. Those are the chances of each winning. So the chances that each of them loses are: 9/11, 11/13, 6/7, 6/7, and 13/15. The chance of all five losing is the product of those fractions: 9/11 x 11/13 x 6/7 x 6/7 x 13/15 = 0.441. So, the probability that one of them wins is 100% - 44.1% = 55.9%.

    If you bet $25 five times (total of $125), your e.v. is 0.559 x $125 = $69.88. In addition, you get four free $25 bets, or $100 in free bets. It matters, of course, how you bet that, but if you were to make four straight point line bets at -110 each, that e.v. would be an additional 100/210 x $100 = $47.62. Together, your total e.v. is $117.50. Sadly, you're $7.50 short of your $125 outlay, so you lose 6%.

    Did I teach you how to fish?

    Don
    Thanks Don..this is exactly the answer I was looking for. And, upon 4th reading, I believe you’ve taught me how to fish . Of course, it’s no surprise that the sports book comes out ahead, even with the bonus offer. Thanks for your time.

  10. #10


    Did you find this post helpful? Yes | No
    Since you like fields of 7, 8, or 9, harness racing would seem to be ideal for you, since almost all races fit that numerical category. Have you looked at the trotters?

    Don

  11. #11


    Did you find this post helpful? Yes | No
    Quote Originally Posted by drunk View Post
    maybe I'm a wimp but I couldn't stand the way they whip those horses
    their whip is very heavy and the driver has a lot of leverage - when it hits the horse it makes a horrible loud cracking sound - it just seems really abusive to me
    They don't whip the horse!! They whip the saddle blanket with the horse's number! USTA would never stand for actually whipping the animals. Surprised you don't know that.

    Don

  12. #12


    Did you find this post helpful? Yes | No
    Quote Originally Posted by drunk View Post
    Don, you can check my math but I read about a sprinter who clocked in 9 seconds for a furlong - one eighth of a mile - of course he couldn't keep that up

    but anyway - I got that to be 53.57 m.p.h._________amazing
    Ha! No, no human did that! A furlong is 220 yards. Almost the same as 200 meters. World record for that distance is Usain Bolt's 19.19 seconds, more than double your number. Bolt's 100 record is 9.58, but he was also recorded between the 60- and 80-meter mark of that race and was clocked at 27.5 mph, which, as far as I know, is the fastest that a human has ever run. Again, half of your number.

    As for harness racing, yes, for many, many years I was quite an expert. Was part owner of a trotting mare for a few years, back in the day. We had Roosevelt and Yonkers Raceway nearby, and later the Meadowlands, not to mention Monticello. I used to go all the time to the International Trot at Roosevelt. I miss all of that.

    Don

  13. #13


    Did you find this post helpful? Yes | No
    Quote Originally Posted by drunk View Post
    Don, you were aware I hope that when I said a sprinter did that I was referring to a horse - a thoroughbred ?
    Ha!! Sorry about that. Too much track coach in me!!

    Don

Page 1 of 2 12 LastLast

Similar Threads

  1. Remedial optimal betting question help (math)
    By BlackHead in forum General Blackjack Forum
    Replies: 2
    Last Post: 02-16-2015, 09:52 PM
  2. Probabitity question for the math guys/gals, non-BlackJack related
    By Nikky_Flash in forum General Blackjack Forum
    Replies: 17
    Last Post: 08-21-2014, 03:23 PM
  3. Paddyboy: Sports betting question
    By Paddyboy in forum Main Forum
    Replies: 0
    Last Post: 07-13-2003, 02:14 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

About Blackjack: The Forum

BJTF is an advantage player site based on the principles of comity. That is, civil and considerate behavior for the mutual benefit of all involved. The goal of advantage play is the legal extraction of funds from gaming establishments by gaining a mathematic advantage and developing the skills required to use that advantage. To maximize our success, it is important to understand that we are all on the same side. Personal conflicts simply get in the way of our goals.