Kelly RoR

S

stophon

Well-Known Member
If you bet full kelly (without resizing bets) i know the RoR is 13.5 percent, however if you bet half kelly how does it affect the RoR?

Does it bring the RoR to half of 13.5? (<-- this doesn't make much sense to me...)
 
Last edited:
blackjack avenger

blackjack avenger

Well-Known Member
One is Not the Other

stophon said:
If you bet full kelly (without resizing bets) i know the RoR is 13.5 percent, however if you bet half kelly how does it affect the RoR?

Does it bring the RoR to half of 13.5? (<-- this doesn't make much sense to me...)
Click to expand...
Kelly is not 13.53% ror, Kelly always assumes constant resizing. However, to answer your question if you have 13.53% ror and cut your bets in half your ror would be 1.83%
 
K

Kasi

Well-Known Member
stophon said:
If you bet full kelly (without resizing bets) i know the RoR is 13.5 percent, however if you bet half kelly how does it affect the RoR?

Does it bring the RoR to half of 13.5? (<-- this doesn't make much sense to me...)
Click to expand...
Generally speaking, forget Kelly for the moment, doubling one's unit roll anytime will make one's original ROR become origROR*originalROR.

So, like BJAvenger said, the "Kelly" risk of .1353 becomes .1353*.1353=.0183 after one chooses to bet "half-kelly" since that doubles the units in one's roll.

Betting .25 Kelly, quadrupling one's units would be a risk of 0.0183*0.0183=.00033.

Conversely, doubling one's unit size and therby halving the number of units in one's orig roll, will make one's risk the square root of one's original risk.

Hence the enhanced danger to one's roll of using fewer units and the reduced risk of using more units - units in one's roll is not linearly related to risk lol.
 
S

stophon

Well-Known Member
So the 13.5% RoR assumes backcounting then because you couldnt place a kelly bet in negative or neutral counts
 
K

Kasi

Well-Known Member
stophon said:
it has to assume placing strictly kelly bets
if it doesnt then im missing something
Click to expand...
Truly, I don't exactly understand Kelly stuff lol. I think it's a way of betting to maximize growth of bankroll. Maybe the logarythmic grow of your roll. Obviously, since I can't even spell it right, I have even less of an idea eaxcatly what that means lol.

It's a way of betting, I think, to produce the best unit-EV to unit-Stan Dev ratio possible given the game and how you want to bet to maximize the growth of your roll. Whether back-counting, maybe only playing hands with +EV or whether "playing-all" hands, including hands with -EV, it's a way to bet to maximize growth of roll and each way will have same risk 0f 13.53%. Or close to it, due to the real world world imposing rational bet sizes.

It does not maximize EV, it maximizes growth. When done correctly, one will double roll in the fewest number of hands compared to betting any other way. I think lol.

It sounds nice. But it's very volatile to one's roll. It's maybe better to bet 1/4 to 1/3 Kelly to keep the volatility down - bet same units at a full-kelly deal but with 3-4 times as many units in roll. JUst a conservative opinion. Half-kelly if you must. Another opinion lol. Sacrifice some EV, perhaps, for lower risk. Double your roll in twice as many, or more, hands as "full-kelly" would predict.

Be properly capitalized.
 
You must log in or register to reply here.
Top