ROI calculation question

jacQues

I know the maths involved for both average ROI and total ROI.

However, is it still possible to calculate the total ROI when using different currencies and not knowing the conversion rate? I think that it would give a (very poorly calculated) average ROI instead...

jacQues

RoundTower

I don't think anyone else knows the formulae for both average ROI and total ROI so you may have to explain it a bit better

Headspace

what is the formula i was trying to calculate my roi today, sharkscope misses games and i want to ban my name anyway i am obcessed with checking it after each session.

jacQues

Basic calculations:

[singe tournament]
ROI% = 100 * ( payout - buyin ) / buyin

[totals]
Average ROI% = sum(ROI%) / sum(tournaments)
Total ROI% = 100 * ( sum(payout) - sum(buyin) ) / sum(buyin)

"payout" are the winnings, 0 if you don't reach the money.
"buyin" is the buyin including reg.
"tournaments" is the number of tournaments played.
"sum(x)" is the total over all tournaments.

Now, I'm interested if the "Total ROI%" can be calculated at all if multiple currencies are used for the tournaments. For example us$, euro and stg. Assuming that the conversion rates aren't available, my question is how to adjust the formula in order to get an approximation of the "Total ROI%". My believe is that this is not possible, since you can only get a badly calculated "Average ROI%" instead.

jacQues

The_Daddy_H

Your average return on investment will still be correct as it is independent of the units being used.

Your total ROI, calculated as you have written it will not work. For instance if you win a tournament in Turkish Lira then add it to dollar tournaments in the sum, you will get a massive Total ROI, (at least as of today). The best thing you can do I think is multiply average ROI by the number of tournaments

Mellor

With the conversation rates not available then it isn't possible, not perfectly exactly.
Best thing will be to maintain a average ROI combining all three, then three separate total ROI counts for each currency.

RoundTower

hmm I don't think that average ROI% is very useful for anything, when you have your total ROI. Do some reading on sums, products, etc of independent random variables.

Mellor

The total ROI is if you are up or down, and by how much. Obviously.

I think, the average ROI shows on average if you win or lose and how much you win per game. If you play the same level it means nothing. Bit a big win (or lose) at a level higher than normal will affect the total ROI but not the average ROI