So — have been messing about with this thing for something like a few months now and it's stuck on my phone, so figured I'd chuck my thoughts in since a lad on another thread asked me a few days back. Am UK based, mainly bet football and racing, small stakes, just so you know where I'm coming from.
How I found it was genuinely pretty stupid — I never could get my head round what an ew return would be once you get five places instead of three. I used to just eyeball it and get a shock. Now I punch the numbers in first, every time, even the boring singles.
The single bet calculator tool is the bit I open most — you put in the price and your stake and it spits out returns straight away, fractions or decimals. It also handles the bigger stuff — trebles returns, lucky 15 and lucky 63, a yankee, and that's where most people I know mess it up. Have a go yourself, it's here no-vig and it's free with no account nonsense.
One thing that actually shifted things for me was the more serious tools. They've got an probability calculator that shows how much the bookie's taking, plus a kelly tool — I stick to fractional kelly because full kelly is terrifying. The dutching one is handy too when I'm covering two or three runners.
It's not perfect mind. Its design is very functional, let's say — not much polish, looks like it was built by someone who cares more about maths than colours. Phone-wise it's usable although the bigger tables need a bit of scrolling. Also there's no app, it's a website and that's it — doesn't bother me but worth saying.
Anyway. Free, no ads shoved in your face, does what it says. If you even now does the maths on paper, give it a go — saved me a load of dumb bets I'd have regretted.