Trivia Math Question, for every 10 cent scalp bet what is your ROI?

Trivia Math Question, for every 10 cent scalp bet what is your ROI? Assuming the lines are close to pk'm and you bet both sides. Before calculating...... what would your guess it would be? Ps. There is a very elegant way to solve this in about 5 seconds.

Without calculating, just blindly guessing, I'll say 2.5%.

Close enough, we have a winner. The easiest way using no math, is to note that of course when laying -110 blindly, we all know we are at a -4.54 % theoretical house edge......so the house (who has a 20 cent scalp when balanced), has a 4.5% edge. Divide by 2, and we are here.

[QUOTE=Fezzik;25269]The easiest way using no math, is to note that of course when laying -110 blindly, we all know we are at a -4.54 % theoretical house edge......so the house (who has a 20 cent scalp when balanced), has a 4.5% edge. Divide by 2, and we are here.[/QUOTE] Actually, IrishTim is completely correct in his answer. I would say that the easiest way to pose a 10 cent scalp is with equal bets, say 100 units, at +105 each way. By inspection, this gives a profit of 5 units for each 200 units bet or an ROI of 5/200 = 2.5%. This, of course, scales to any scalp centered around +100, thus the ROI (in %) is = scalp (in cents)/4. The farther away the scalps are centered from +100, the less the value of ROI.

Yes, but it is easier to have a 10-cent scalp on a higher line because the lines move more at -200 than they do at -110. In other words, you will have more opportunities at that lesser ROI, so in theory, it should cancel out. Do scalping opportunities occur as often as they should, though, at the higher lines?

[QUOTE=joelshitshow;25292]Yes, but it is easier to have a 10-cent scalp on a higher line because the lines move more at -200 than they do at -110. In other words, you will have more opportunities at that lesser ROI, so in theory, it should cancel out. Do scalping opportunities occur as often as they should, though, at the higher lines?[/QUOTE] Of course, due to the nonlinearity of the ML mechanism, lines do move more at -200 in terms of cents than at -110, but they don't necessarily move more in terms of breakeven percentage which is the actual metric that moves should be measured with. Here's a quick quiz: Betting 1 unit on the favorite and then scalping the dog at the proper bet to profit the same with both bets, which provides the best ROI? Case Scalp-Cents FavML DogML A. 10 105 105 B. 15 -160 +175 C. 40 -280 +320 D. 200 -800 +1000

I'd say C) 2.57% ROI

[QUOTE=CraigRAS;25311]I'd say C) 2.57% ROI[/QUOTE] Correct, the ROIs are: A. 2.50% B. 2.14% C. 2.57% D. 2.06% Note the real ROI should be measured per unit time, i.e. how long are the two bets in place before the scalped profit and dual bets return to the bankroll. The most timely scalps can occur simultaneously for games that are played on the same day as the bets are made. Others like football during the regular season can span an entire week. NFL week 1 and CFB bowl games can span several weeks up to a month. Finally, season win totals, season long props, and futures to win divisions or titles can span 4 months to a year. A scalp that resolves within a week and can be rebet on similar scalps gives an accumulated ROI of roughly 20 times that of a season win total scalp that is bet August 1 and cashes January 1.

Answer is C assuming that the scalps shown are balanced around the correct line, i.e. with -280, +320 scalp we'll assume -300 is correct line. A: 2.5% B: 2.16% C: 2.63% D: 2.22%

Not looking to contradict; not sure if your assumptions are the same as mine. If actual probability of scalp C is -300, then on every 4th trial the book will lose the 40 cents out of the 280 + 100 = 380 collected. 1/4 * 40 / 380 = 2.63% What are you assuming for the probability the dog covers? Can you show your math for C, please?