% of bankroll to bet?

[jackad]

If the results of using a particular method in a 200 race sample show a 20% win frequency and a 20% ROI, what percentage of bankroll would you bet with this method on forthcoming races?
Jack

[cj]

It all depends...did you hit one $199 horse and a whole bunch of $3.60 horses? Things like this matter, in my opinion. The best thing I've seen is Barry Meadow's Win Bet Chart from "Money Secrets at the Racetrack", and is also included in Steve Fierro's "The Four Quarter's of Horse Investing". Check it out if you get a chance.

CJ

[Foolish Pleasure]

I would not tie your bet amount to a perceived advantage, regardless of what you may have to pay to have someone implore you to do it.

There is such a thing as market efficiency and the higher the perceived advantage, typically the higher the error.

Go find a decent risk of ruin model and plug in your parameters, it will yield the best risk/return answer and ultimately the ideal bet amount.

[Dave Schwartz]

Jack,

The simple answer is this:

You say you have:

20% hit rate
+20% ROI

SInce Optimum Bet is nothing but ROI / odds...

$200 = 100 bets @ $2
+ 40 = 20% ROI
------
$240 = total return
/ 20 = number of wins
------
$12.00 = avg mutuel = 5:1

Therefore, Kelly says, "Bet 4% of bankroll."

Your mileage may vary because this formula assumes that all the winners are at precisely 5:1.

[formula_2002]

jackad

Based on the information given, don't bet any thing that would require you to ask the question "how much should I bet."

Good Luck

Joe M

[Holy Bull]

Any type of theoretical bet size calculation is moot in my opinion cause its pretty naive to "expect" a 20% roi going forward based only on 200 plays.

I'd say play 1/2% tops and if the ROI holds up as sample size grows, increase accordingly.

[kenwoodall]

I agree 20% wins leaves a lot of room for error, but you know th exact method used. I am curious about the test period being 2000.
Any 1 method that produces 29% profit is worth looking into as I consider that a minimum goal.

[hurrikane]

20% is fine. the sample size is a little small. I'd say start slow.

Biggest thing about this is...you gotta have staying power. at 20% you could have a losing streak of over 30 straight losses. Can you handle that? Also, what if you have 29 straight loses, one small win, and then 30 straight loses after that? I guarentee you it will happen at some point if you are doing spot play.
4% will kill you. 2% can kill you, 1% may be fine, 1/2 is safe.

I like what Holly said..start at 1/2 and see if you're ROI and the win % holds.

Also, how big is you bankroll? At a 20K bank 4% will change some pools. Hell, 1/2% could change some pools. That will have an effect on your results. You haven't figured your money in the pool yet.

Also, what is the IV on your play? Did you make most of your money on a couple of big prices. If so...you may not be around to make the bet on those couple of big prices. There nothing worse than looking at a nice juicy payout that you didn't bet on while your bankroll has been fortunate enough to be bet into the losers. Spot play is a grind..you have to be patient and not, as most will do, jump ship when the tough times come around.