Long Run and Parlays Questions

[CrushinFelt]

I've been lurking and occaisionally posting here for a few weeks. I know there have been a few comments (maybe a topic?) about this before, but either the search function sucks or I just don't know how to use it because I can't find anything.

Is there a similar idea of long-run returns in baseball? Is it determined by the number of bets or seasons or the like (I'm sure there is but I couldn't find anything using the search fcn)?

I have been betting since the beginning of the regular baseball season doing primarily 4-Team parlays at $5 a piece (the occasional $10 parlay) and I've turned $100 into just over $600. I get about 10-1 on the payouts. I'm also definitely not a Sharp, I just look at pitching match-ups and I guess my own line before I look what they actually are. If I deem that I am getting a better price then I'll add it to a parlay. Also, if there are two games that I think are locks (almost regardless of price) I'll use them as my base for my parlays and vary what other two games I put with them. Obviously when I get those games right I have a great shot of having a huge day.

This is likely me getting a bit lucky, but I'd also like to know what quantifies a parlay as -EV. All I've ever seen is regulars bitch about them but they never take the time to give a brief description why. If it is a longer answer than I appear to think it is, then is there a book or web site that talks aobut that specific topic?

Here's my brief little math segment which may be silly, I'll let you all decide:

Let's say that on the average 4-team parlay I am getting 10-1 on my payout.

If there's a 50/50 chance of me hitting each game individually then I need (1 / (.5*.5*.5*.5)) or 16-1 to get fair value on my parlay.

If I think I will be right 60% of the time then I only need (1 / (.6*.6*.6*.6)) or 7.71-1 to get fair value on my parlay. Clearly if I am getting 10-1 then I am getting great value.

In fact, if I think I can pick the winners of my 4 games approximately 56 percent of the time then I will be getting fair value on my parlay.

Is it too much of a stretch to think that I will be right 56% of the time or more?

I dunno, I'm sure there are things I am overlooking. I hope someone takes the time to point me in the right direction and tell me what I'm overlooking. I do not doubt I am overlooking something, but this simple math is the reason I wonder about the idea of parlays being -EV.

Perhaps we can get a useful thread going that can be stickied or something to which you can point the new fools towards when they inquire about parlays.

Thanks,
CF