Rules to live by.

[Thremp]

Its not "nearly" impossible. Its completely 100% impossible. How can you lose money you don't wager? You'd never wager your entire bankroll only portions of it. So how the **** could you ever reach 0?

[Grind-It-Out]

Its not "nearly" impossible. Its completely 100% impossible. How can you lose money you don't wager? You'd never wager your entire bankroll only portions of it. So how the **** could you ever reach 0?

Technically, that's correct. It's impossible to reach true zero. However, you can reach the point where your bankroll is below the minimum bet size.

That being said, you're more likely to win the lottery than to have that shit happen.

[TakeIt]

There has never been a person to go broke using full Kelly. Even if you overestimate your edge, you can't even go broke.

semantics.

[Thremp]

http://en.wikipedia.org/wiki/Semantics

Sadly, never and sometimes aren't going to get confused except by the deceitful or ignorant. Not semantics.

[That Foreign Guy]

Find people smarter than you and copy them.

[rise]

go to the other side and open up shop and book the action look for parlay betters

[RaginCajun]

Money Management is the biggest key to winning. Never ever chase when losing, I know people who double, and triple bets to make up for loses, never do it, unless you cannot help it. This is what I do, evaluate the game, match ups injuries, weather (outdoors only lol) and then give the game a line, then check what actual line is, if you are on the money or close take the side you like, if the other side is a bigger fav then what you evaluate it as, place more money on your side, never let the so called "line is telling me something game" you will talk yourself out of making a lot of money when you walk away or choose the other side because you think someone knows something. GOOD LUCK

is there any mathematical formula or something to make a prediction on the line of the game or anything?

[Sawyer]

Do you think all pros on earth use kelly? of course not. I was using kelly in past but then dumped it. flat staking is good or have a unit scale system with a narrow range like 2-3-4. there shouldnt be a huge difference between your stakes. if you bet 1 unit on 1 game and 20 unit on another game then varience will increase..

[Grind-It-Out]

Do you think all pros on earth use kelly? of course not. I was using kelly in past but then dumped it. flat staking is good or have a unit scale system with a narrow range like 2-3-4. there shouldnt be a huge difference between your stakes. if you bet 1 unit on 1 game and 20 unit on another game then varience will increase..

I don't know many people, pros included, that use full Kelly. But it's not because they doubt it, it's because they doubt their own ability to accurately determine expected winning % for games.

That being said, I also don't know any pros that flat stake. It just doesn't make sense. Why bet the same on a game where you have a 25% edge as a game where you have a 5% edge? While people can't be 100% accurate in predicting win %, most have a good idea of the rough win %.

[dialup_king]

Its not "nearly" impossible. Its completely 100% impossible. How can you lose money you don't wager? You'd never wager your entire bankroll only portions of it. So how the **** could you ever reach 0?

if you think something has a 100% chance of happening, Kelly says to bet your full bankroll

[Grind-It-Out]

if you think something has a 100% chance of happening, Kelly says to bet your full bankroll

If something had a 100% chance of happening, then it would happen, so it's impossible to lose the bet.

[durito]

if you think something has a 100% chance of happening, Kelly says to bet your full bankroll

Kelly doesn't account for prediction errors. If something really does have a 100% chance of happening and you have a 100% chance of being paid, go ahead and bet your whole roll.

[Data]

There has never been a person to go broke using full Kelly. Even if you overestimate your edge, you can't even go broke.

That is not true. Even while making +EV bets, if you bet twice Kelly then your EG=0, it is negative if your Kelly fraction is more than 2.

[BeatingBaseball]

I always thought people just chased because they either had no self control, or because they were working with a limited bankroll and were willing to accept the added risk. If people think that landing on Tails on the first flip means that Heads now has a 75% chance of occurring on the second flip, God help them lol.

If "people" think the game of professional baseball at the major league level is analagous to flipping coins in any mathematically exact way, God help them. lol

[Thremp]

That is not true. Even while making +EV bets, if you bet twice Kelly then your EG=0, it is negative if your Kelly fraction is more than 2.

Um... wtf?

[Data]

Nobody has ever gone broke using Kelly. In fact, it's nearly impossible to do so. If people claim to have done so, it's simply because they overestimated their winning %, which is not Kelly's fault.

Its not "nearly" impossible. Its completely 100% impossible. How can you lose money you don't wager? You'd never wager your entire bankroll only portions of it. So how the **** could you ever reach 0?

First of all, it is not just possible but guaranteed if overbetting results in Kelly multiplier being 2 or higher. And, sure, the main problem with Kelly is the high risk. Almost everybody knows that but, perhaps, tend to forget.

The less obvious but more important for understanding Kelly is realizing that "going broke" does not mean the same as Kelly bankroll being zero. People "go broke" when their assets are less than their liabilities and become insolvent. They have zero gambling bankroll but their Kelly bankroll is far from zero. It is pretty much like 0ºF (going broke) vs. 0ºK (zero Kelly bankroll).

So, it is possible to "go broke" in layman's terms not just while making +EV bets but even while maximizing EG.

[Ian]

When making a wager at a B&M sportsbook, I put the slip in my wallet and as soon as I get home I put my slips in the same safe place each time. I would go on mega tilt if I won a big bet and couldn't find the ticket.

[Grind-It-Out]

That is not true. Even while making +EV bets, if you bet twice Kelly then your EG=0, it is negative if your Kelly fraction is more than 2.

But why would you bet double Kelly? The only reason is because you are overestimating your win %. Once again, Kelly does not account for inaccuracies in your predicted win %. But, if you do go bankrupt, it's not because of Kelly, it's because of your inability to put an accurate number on games. This is why people rarely use full kelly in real world applications.

[Inspirited]

http://drbobsports.com/essays.cfm?p=1

[Thremp]

First of all, it is not just possible but guaranteed if overbetting results in Kelly multiplier being 2 or higher. And, sure, the main problem with Kelly is the high risk. Almost everybody knows that but, perhaps, tend to forget. The less obvious but more important for understanding Kelly is realizing that "going broke" does not mean the same as Kelly bankroll being zero. People "go broke" when their assets are less than their liabilities and become insolvent. They have zero gambling bankroll but their Kelly bankroll is far from zero. It is pretty much like 0ºF (going broke) vs. 0ºK (zero Kelly bankroll). So, it is possible to "go broke" in layman's terms not just while making +EV bets but even while maximizing EG.

Cool story bruh.

[mizzoujohn]

BB,
Unless you have some reason to believe that a loss in Game #1 has some actual positive influence on winning Game #2 (which is highly unlikely), then you don't have any justification for INCREASING your bet size on #2, which is what chasing tells you to do.

Take a team like NYY... They have 81 home games. We all can assume they will at least go 50-31 in those games. So, if they lose a game #1 in a home series, the next game is a higher % chance of winning because we just took one of those 31 losses out of play. I mean, for a team we have predicted (and will) win 50+ home games, every home loss only increases my confidence in them winning the next game.

[Optional]

Does that mean if they got to 50-20 you would think they were a lock to lose the next 11 in a row?

[bztips]

mizzou: We "all can assume" that a coin tossed 100 times is going to land on heads very close to 50 times. Based on your logic, if after the first 80 tosses it's come up heads only 30 times, I guess you'll be betting heavily on heads for the next 20 tosses.

All I can say is that the books LOVE to take action from people like you.

[heelan13]

hahahahaha i love this forum. great topic! keeep up the thinking!!!

[That Foreign Guy]

Once they lose a home game you need to re-evaluate your prediction of them being a 50-31 team.

[illfuuptn]

Omg! I've never thought of that! You've figured it out. Wow I wish I was the one who thought of this. You'll be famous pretty soon dude. Even better bro...if you've lost 7 bets in a row you should bet every asset you have because it's like 99% you win the next game.

[bztips]

yep, in the immortal words of Bob Prince (famous Pirate announcer of the 50s and 60s), "the more you lose, the closer you are to winning"

[Sactown]

I'm trying to grasp the Kelly system. So lets say for my limited math odds, that all bets are -110 and we are talking about NFL. If I find Team A at -4.5 to be a 5% edge. How should my edge change if the line were to change from -4.5. For example if it goes from -4.5 to -3. Or what if it goes from -4.5 to -7, would this mean my edge would be on the other team possibly? Is there an equation for each .5 it goes up or down or am I making absolutely no sense

[chachi]

Never bet for or against your favorite teams. Leave your emotions out of it...

Indeed ... excepting as a hedge I always have followed this rule
(I was on Fulham to win the Europa Cup for £5 at 250/1 and was forced to bet Atletico against it)

[Grind-It-Out]

I'm trying to grasp the Kelly system. So lets say for my limited math odds, that all bets are -110 and we are talking about NFL. If I find Team A at -4.5 to be a 5% edge. How should my edge change if the line were to change from -4.5. For example if it goes from -4.5 to -3. Or what if it goes from -4.5 to -7, would this mean my edge would be on the other team possibly? Is there an equation for each .5 it goes up or down or am I making absolutely no sense

That has absolutely nothing to do with Kelly. Kelly doesn't tell you how to predict win %, it just tells you how much to bet for a given win %.

If there was a simple, accurate answer to your question, everyone in the world would be a professional sports bettor.

[djiddish98]

I'm trying to grasp the Kelly system. So lets say for my limited math odds, that all bets are -110 and we are talking about NFL. If I find Team A at -4.5 to be a 5% edge. How should my edge change if the line were to change from -4.5. For example if it goes from -4.5 to -3. Or what if it goes from -4.5 to -7, would this mean my edge would be on the other team possibly? Is there an equation for each .5 it goes up or down or am I making absolutely no sense

I'll take a stab at it - if based on some independent calculation of your own, you find a 5% edge for Team A at -4.5, then, using full kelly, you would like to place a bet that would win 5.5% of your bankroll (at -110). That seems simple enough.

If the line changes - for example, it drops down to -3, you would re-calculate your edge again based on your independent calculation. The edge you come up with at spread -3 (i believe) depends on your calculations. I don't think there's a specific gain from the line dropping to -3. It's dependent on how you think the outcomes of the game are distributed.

For an extreme example, If you thought (based on your calculation) that all the probable outcomes for the game were between the fave winning by 4 and 6 (100% chance that Team A wins between 4 - 6),
then if the spread was at -3, you would bet 100% of your bankroll on the fave, since your calculation says there's a 100% chance that the fave will win by more than 3. And if the line was -7, you would bet 100% of your bankroll on the dog, because you've again determined that the fave is only winning by a max of 6, so it has a 0% chance of winning by 7.

Again, extreme example - if a calculation came up with this result, I would seriously question the calculation first before betting it.

Also, someone correctly me if I'm wrong.

[Poogs]

I think you're confused as to what kelly is (the guy who asked the original question.) Kelly just tells you what percentage of your bankroll to bet on a game based on your edge. However knowing your edge is something that I'm sure you can't do based on your question. Don't worry about kelly, I personally don't use it and do just fine. Its not too hard to estimate your edge and bet accordingly.

[Pancho sanza]

I'm trying to grasp the Kelly system. So lets say for my limited math odds, that all bets are -110 and we are talking about NFL. If I find Team A at -4.5 to be a 5% edge. How should my edge change if the line were to change from -4.5. For example if it goes from -4.5 to -3. Or what if it goes from -4.5 to -7, would this mean my edge would be on the other team possibly? Is there an equation for each .5 it goes up or down or am I making absolutely no sense

If you are confident in your analysis, ie that you do in fact have a 5 % edge at -4.5, then you would bet more should the line drop to -3.

If it were to jump to -7, you might now want to take the dog, depending on what you made the fair line.

Lets say you made the fair line -6, game opens -4.5, you lay it, line moves up to -7.

Both lines (-4.5 and +7) are +ev so naturally you would take the +7.

The amount you would wager on the +7 would depend on how much you managed to get down at -4.5.

[kman008]

If something had a 100% chance of happening, then it would happen, so it's impossible to lose the bet.

i wonder if this is why i'm dead broke

[ArminMD]

never bet your eating money.

+1 .