Kelly vs 10 % Bank

If you're a winner with a defined edge, Kelly staking is correct.

The blurrier those lines get, the less correct it becomes, but you should still understand the principles and work something out around them.

Other than that, not enough information on the kinds of bets you're having to know if 10% is too large or too small (although it's probably too large)

A lot of my betting is based on laying so effectivly backing odds on shots eg laying side b @ 4.00 for a liability of 10% when I make side b a 5.50 chance

In this example I kelly states I should use 24% of my bank, half kelly would be more appropriate so 12 %.

Therefore I would be betting more than 10% of my bank, can't decide if this is a sensible approach

What is your perceived % chance of your bet winning? Is it 44% roughly?

If your strategy appears to win by atrrition, rather than by jumping in a filling your boots in if and when you perceive good value, then perhaps Kelly is not the best way actually to go.
It takes a lot of real skill to implement and can be more dangerous than helpful if you are not truly an expert punter.
If and when I try it I find myself chickening out on its suggested bet size more often than not.
And if you start to do that,it all becomes a guessing game, do I or don't I bet the Kelly amt.

And Lori please don't jump down my throat yet again.
I'm just stating my personal perceptions of and problems with Kelly.
I'm more into protecting capital than maximising profits.
Exactly as I am in all other " investing" markets.

I'm more into protecting capital than maximising profits.

These are the same thing, as if you don't bet big enough, you're giving away future capital.

Now that's an interesting theoretical answer.
Can't really argue with it on that level.
But practically I'm not so sure.

Thought you might like it worded that way, we've done all the other things before... I do agree it can be dangerous in the wrong hands.

By: This user is online. DFCIRONMAN
Date Joined: 04 Dec 04 Add contact | Send message
When: 10 Aug 11 20:50 Joined: Date Joined: 04 Dec 04 | Topic/replies: 16,747 | Blogger: DFCIRONMAN's blog
What is your perceived % chance of your bet winning? Is it 44% roughly?

In the example I gave my percived chance of winning is 81% which is fair enough because the bet covers 66% of the market as standard

The thread title should not be -

Kelly vs 10 % Bank


as it is really you v 10% of Bank !

If you get the "probability" wrong ....then only yourself to blame etc etc

fair point but that's the same with everything

not having a dig as you're right, just more interested in if this is a better feisable staking plan

Something not "right" I suspect re the figures .......perhaps Lori can confirm this?

LAYING using KELLY "confuses " me a lot!!!!!

81% ....is that not you in effect saying the odds are 9-2? As opposed to 11-2?

Ash
In the outside world of investing Kelly is used a lot by savvy investors by never to my knowledge over their whole portfolio.
That is, certain subsections of a portfolio may be jazzed up a bit by increasing the debt leverage in that section ( which is in reality a Kelly application) if it is perceived that a very good value opportunity is presenting itself there.
But that would never happen over the whole portfolio, large swathes of which are played very conservatively, sometimes with no leverage at all.
So if you are a professional gambler going into many diverse uncconnected positions all the time of varying dergrees of probability and perceived value, there may be cases to apply Kelly and conversely not apply it.
The point is not too concentrate too much in any one particular approach ever.
If you do that, all it takes is one flash crash ( or very unlucky result) if not to bring down the whole house then to set you back to where you were a long time ago.
Kelly is good but only in moderation.
Personally I find the yields on successful gambling strategies high enough as they are, without any need to try to " maximize" profits by attempting Kelly. But that's just personal.

Hope you don't see this as arguing Lori.
I concur with you on the theory of Kelly, but question its application on a generalised basis to gamblers, particularly most of those on here.

Betting bank £  100               

Please complete all white boxes. The others will be calculated for you.
      
Odds available  4        
Commission %  5
              Win probability % 19   
Actual odds  3.85              Implied odds 5.2632   
            
Value index               If value index is below 100, stake will be negative – do not back

            Stake % of bank  - 9.42   
          Stake £ - 9.42   


Well that is how I used your figures.......and shows NEGATIVE 9.42%........presumably that is the STAKE TO RISK if LAYING?

If your ODDS AVAILABLE is 3-1....then the calculator shows - 23.63% to use.....which might be what you mean ....3-1 ...and not 4-1?

if you do 100/5.50 it gives you 18.18 (the % chance of side b)

take 18.18 from 100 and you get 81.82 (the chance of side a winnning of drawing)

so accoding to kelly

http://www.albionresearch.com/kelly/default.php

the odds available are 4.00 (1/3) and your chance of winning is 81%

so with a £1000 bank it is advising that you risk £240 on this bet (lay side b to win £80)

if you do 100/5.50 it gives you 18.18 (the % chance of side b)

take 18.18 from 100 and you get 81.82 (the chance of side a winnning of drawing)

so accoding to kelly

http://www.albionresearch.com/kelly/default.php

the odds available are 4.00 (1/3) and your chance of winning is 81%

so with a £1000 bank it is advising that you risk £240 on this bet (lay side b to win £80)

DFCIRONMAN
Date Joined: 04 Dec 04 Add contact | Send message
When: 10 Aug 11 21:50 Joined: Date Joined: 04 Dec 04 | Topic/replies: 16,751 | Blogger: DFCIRONMAN's blog
If your ODDS AVAILABLE is 3-1....then the calculator shows - 23.63% to use.....which might be what you mean ....3-1 ...and not 4-1?

Try putting your figgures through the link I posted this may clear up the confusion I hope

you've also got to remeber to switch your odds round when laying

eg 3/1 becomes 1/3

18.18% = a 9-2 shot....not a 11-2 shot though..............

The point is not too concentrate too much in any one particular approach ever.

Good point frog and I couldn't agree more

I have many different types of betting however this one particular strand is something that I believe can be greatly improved by looking at other areas of staking

ok ...you meant that it was 3-1 odds available to lay ......and 9-2 shot you considered it to be ( as you used 18.18%)........but you did say above that you considered it to be an 11-2 shot ( 15.38%)....therefore based on initial post the STAKE to risk on LAY would be 29.16 %.......

Slight differences in the PROBABILITY will lead to large differences in STAKING....

Your calculation is based on 4s BF and 5.5 BF odds.......fair enough .......therefore I am now "clear" on what you mean....


Though with FOOTBALL.......It really is "difficult" to be "accurate" re odds, as such a volatile sport............

BTW ...are you LAYING ENGLAND Under 20s at 4s BF?



Looks a "good" bet if you are


I suspect ENG though have quite a bit of energy left in tank ....as they have done very little SO FAR in comp....so who knows ...they might win


I will be laying em though

4.50 = 7/2 = 22.22%

5.50 = 9/2 = 18.18%

6.50 = 11/2 = 15.38%

LAYED at 3.95 BF odds

GL with bets........whatever STAKING method you are using......LORI knows a lot about KELLY STAKING ....but there must be umpteen threads you can find on this subject?

DFCIRONMAN
Date Joined: 04 Dec 04 Add contact | Send message
When: 10 Aug 11 22:16 Joined: Date Joined: 04 Dec 04 | Topic/replies: 16,755 | Blogger: DFCIRONMAN's blog
Your calculation is based on 4s BF and 5.5 BF odds.......fair enough .......therefore I am now "clear" on what you mean....


Though with FOOTBALL.......It really is "difficult" to be "accurate" re odds, as such a volatile sport............


If you look at final season tables vs results (over 20 years) ie results of teams in a certain poition against teams in another position you can get an average of what the odds should be.


Therefore try and predict the final table for the season we are in and you have a starting point

add to that other factors eg, recent form, injuries etc and you can start building a price.

Also not laying England because I can't put my maths around it

The "heat" should be enough to beat them........should suit NIGERIA players.

Is that PC ( politically correct) to say these days ?

Just medically "correct" !!!

NIGERIA appear to be quite "happy" to play for extra time.......when they will up the pace and ENGLAND likely to be struggling.

Dangerous game to play ...as ENG have sheer "power" and all it takes is one good set piece and they might steal a lead.

Pace + skill against sheer power.......generally PACE wins over POWER.....

Game would really come to life should ENG take lead though ......so as I have adjusted position on match......reducing liability on ENG and have 0-1 /0-2 and 1-2 as covers.....with main bet now LAY on 0-0....hoping NIGERIA win, or one of scores shown...

Nothing to do with KELLY though .....my apologies for posting re this match.

This is my last post on the this match....

GL with using KELLY.

10% might be your optimal Kelly Stake and you never knew it! The best Kelly stake for your system depends on your bank size, strike rate and edge. Plug those factors into a Kelly calculator and find your answer.
In my blog Mr.Kelly has run $20 into a few thousand since March. I've written a bit about Kelly and Shannon and other stuff there if you are interested.