LF a spreadsheet to take basic bets for racing.
January 12, 2010 7:18 PM   Subscribe

My friends and I want to run a pig race with betting for charity and aren't able to find or make a spreadsheet to do the simple odds for us. Do you know where to find one?

We live in a sleepy Nicaraguan fishing village, but we have a good local NGO that we try to come up with new fundraising ideas for. The other night we thought that racing my pigs would work well. Gringoes place simple bets (win... maybe place/show. no trifectas or weirdness), we collect 15% of all bets for the charity, and payout the rest based on odds determined by the bets placed less the NGO's 15%.

i thought it would be easy to find a spreadsheet i could plug four pigs into, 15% takeout for FSD, put in the bets and write the odds until closing on a chalk board, run the pigs and read the payouts. i was dead wrong.

i suck at excel. does anyone know of a simple sheet like this?

posted by bryak to Sports, Hobbies, & Recreation (6 answers total) 4 users marked this as a favorite
Hello there.. so i made a google spreadsheet that should work, based on my understanding of what the question is asking.

All you need to do is change the values in red to reflect how much is placed on each pig. I put in some dummy values to show you how it works. The spreadsheet should calculate the rest! Telling you the NGO share, the betting pool (total money minus the 15%), and the payout should the pig win.

Mefi mail me if you need any changes or need any help. . You should be able to export it as a regular Excel document from the site.

Have a look here:

(sorry - i can't seem to get a clickable link working in this answer)
posted by TheOtherGuy at 1:27 AM on January 13, 2010

To clarify, the payout is per $1 bet.

If a person bets $4 and the payout figure is $3.50. Then he will win 4 * 3.5 = $14.

Test it out to make sure I don't bankrupt the charity!
posted by TheOtherGuy at 1:36 AM on January 13, 2010

I used to work as a sysadmin for some bookies and surprisingly odds are not necessarily calculated strictly to a formula. there was a formula for working out odds, but it turned out not to be the case.

Bets can be worked out as a percentage (so probability (i.e. all the bets) adds up to 100% + margin is added on top) but this can't account for the spread of how money will be placed. On course book making, in particular functions as a market for risk: as more money is placed on a particular bet the bookies lower the odds in order to avoid having to pay out (and raise them on bets they aren't taking much money on) . I suspect some of the bigger bookmakers do it programatically but smaller bookmakers often follow the on course bookmakers and they do it on the fly as far as I could tell (it was a strange world, everything was done on handshakes for example).

In your case however you seem to want to take bets first then work out the odds. This is similar to a totalisators aka the tote also known as parimutual betting where odds change according to the amount wagered.

The calculation is relatively easy as long as you express bets as a decimal odds.

You can work out the decimal odds as (Total of all stake - your percentage) / stake for that outcome and payout = stake x decimal odds.

Say you have four pigs. Bets are as follows Pig A 5 favorites, Pig B 3 favorites, Pig C 2 favorites, Pig D 1 favorite(total stake is 10 favorites handily enough).

Pig A stake 5 decimal odds = (10-15%=8.5)/5 = 1.7
Pig B stake 3 decimal odds = (10-15%=8.5)/3 = 2.83
Pig C stake 2 decimal odds = (10-15%=8.5)/2 = 4.25
Pig D stake 1 decimal odds = (10-15%=8.5)/1 = 8.5

To convert to American (Moneyline) odds if its greater than 2.0 subtract 1 then multiply by 100, if its less than 2 then divide 100 by (odds minus) one and make it a negative number.

To convert to British (Fractional) Odds take away one (this represents the stake which is always returned with the bet) and convert the decimal to a fraction, in practice you are likely to end up with some odd fractions though.
posted by tallus at 1:45 AM on January 13, 2010

sorry i misunderstood.. now you can add each bet to the spreadsheet.. just put the name in the table to the right.

Copy the formula in column L for as long as you need. The table to the left will give you a live update of how much money you have, the NGO cut, and the payout. The table on the right will automatically calculate the payout if their bet is successful.

Only caveat.. if a person wants to place a bet on more than one pig, enter each bet on different lines.

else the payout calculation will stuff up!
posted by TheOtherGuy at 1:55 AM on January 13, 2010

thanks for the good inside info, tallus. i like understanding what's going on with the numbers. plus, that will be handy to converting to racing looking odds to make people feel like they're at a real race.

TheOtherGuy... the pig totaliser is AWESOME! i can't wait to see how this goes down, and to see if my little guys can even run.

Thanks much y'all.
posted by bryak at 5:53 AM on January 13, 2010

glad to help. Send me a mefi mail when the race has been run and won. would love to hear how it went. Any problems.. let me know.
posted by TheOtherGuy at 8:55 AM on January 13, 2010

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