New Posts For Thread: question for the maths boys..https://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boysa bag has 3 balls of different colurs, one green, one blue and one orange.I'm offered odds of 4/1 to pick out the orange ball. Obviously the true odds are 2/1. How do I express my edge mathematically?Is it (q-p)/q*100, where q=true odds as percentagethanks all - knew i was wrong but couldn't see wood from trees..https://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=518055695#518055695thanks all - knew i was wrong but couldn't see wood from trees..Thu, 29 Mar 2012 11:28:32 -0500one more answer can't hurt.To put it in your language:(q-p/p)*100=(0.13/0.2)*100 = 67%you just got the choice of divisor wronghttps://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=518010221#518010221one more answer can't hurt.To put it in your language:(q-p/p)*100=(0.13/0.2)*100 = 67%you just got the choice of divisor wrongWed, 28 Mar 2012 06:34:38 -0500Let F=fair oddsLet P=payoff oddsHouse advantageF-P/[1+F]Punter advantageP-F/[1+F]So in your example4-2/[1+2]=2/3=67%https://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=518009403#518009403Let F=fair oddsLet P=payoff oddsHouse advantageF-P/[1+F]Punter advantageP-F/[1+F]So in your example4-2/[1+2]=2/3=67%Wed, 28 Mar 2012 05:46:23 -0500Edge is your change in EV. (expected value).Expected Value is Sum of Probability*Profit over each outcome. At 4/1 you win 4 pounds 1 in 3 times and lose 1 pound 2 in 3.So, your EV is 4*(1/3) - 1*(2/3)=2/3 = 66.7% edge.Probability(Win)*Profit - Probabhttps://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=517991809#517991809Edge is your change in EV. (expected value).Expected Value is Sum of Probability*Profit over each outcome. At 4/1 you win 4 pounds 1 in 3 times and lose 1 pound 2 in 3.So, your EV is 4*(1/3) - 1*(2/3)=2/3 = 66.7% edge.Probability(Win)*Profit - ProbabTue, 27 Mar 2012 15:04:49 -0500Every £1 invested returns £1.67, so ROI (for me the same as edge) is 66.67%.Imagine 3 goes, staking £1 each time. Probabilistically, you will win once.Total stake = £3Returns = £5Profit = £2 ROI = Profit/stake = 2/3https://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=517991149#517991149Every £1 invested returns £1.67, so ROI (for me the same as edge) is 66.67%.Imagine 3 goes, staking £1 each time. Probabilistically, you will win once.Total stake = £3Returns = £5Profit = £2 ROI = Profit/stake = 2/3Tue, 27 Mar 2012 14:44:56 -0500a bag has 3 balls of different colurs, one green, one blue and one orange.I'm offered odds of 4/1 to pick out the orange ball. Obviously the true odds are 2/1. How do I express my edge mathematically?Is it (q-p)/q*100, where q=true odds as percentagehttps://community.betfair.com/general_betting/go/thread/view/94082/29028111/question-for-the-maths-boys?post_id=517990589#517990589a bag has 3 balls of different colurs, one green, one blue and one orange.I'm offered odds of 4/1 to pick out the orange ball. Obviously the true odds are 2/1. How do I express my edge mathematically?Is it (q-p)/q*100, where q=true odds as percentageTue, 27 Mar 2012 14:27:48 -0500