apologies if this is the wrong board. I am working on a program to help with calculating odds in horse racing, however I am getting different results to all online each way odds calculators. I think it must be an issue with my understanding of odds rather than issues with the code.
If I put a 10p each way bet on a horse (20p in total), with placing horses paying 1/4. If the horse has odds of decimal 100.0 (99/1), and it places, its paying out odds should be 25.0 (24/1), and pay £2.50 (profit of £2.30). However all of the online each way bet calculators such as https://www.aceodds.com/bet-calculator/each-way.html are returning £2.58 (profit of £2.38). Is there something I am missing when it comes to each way odds/removing the stake? Thank you.
The $1/4$ calculation applies to the odds, not the decimal.
In this case $1/4$ of odds $99/1$ is $24.75/1$.
So, if your stake on the place part of the each way bet is $10$p you'll get back $£2.475+£0.10=£2.575$ which is presumably rounded up to the nearest penny, so $£2.58$.