The large and strange and awesome Reddit community has a lot of facets, in case you didn’t know. One of the recurring features on Reddit is IAmA where people post about their interesting job or accomplishments or circumstances.

On IAmA, you’ll see topics like “IAmA 34 year old who has had a glass eye since age 2” and “IAmA former driver for a prostitue” and “IAmA person who is locked in a room with a violent psychotic who’s currently sleeping for the next three hours with only my IPhone and a panic button” and “I Am Louis C.K. (yes, he really did it).”

Today, a Reddit user called ‘AdvantageGambler’ engaged in an IAmA Professional Gambler question and answer session. Now, users are supposed to provide proof of their IAmA claims and ‘AdvantageGambler’ provided some proof. It’s a screen shot of his Pinnacle account and it shows a balance of $980,288.01.

Is the screen shot legit? Well, it looks it. But it’s impossible to be definitive. But what adds some credibility to the screen shot is the question and answer session.

Before we get to the Q&A, you should read AdvantageGambler’s introductory statement:

I’ve been gambling professionally (full-time) ever since I turned 18 (ten years ago). The bulk of my income over the last decade has been sports betting, though as my username suggests, I’m a broad-spectrum Advantage Gambler.
90%+ of my income comes from sports betting, online gambling (non-poker), and blackjack variants (card counting). While I do play poker from time to time, I only do it when I’m very bored of my other jobs or there’s a lull in the sports betting world – or when there’s a great game I can’t pass up on.

So the bulk of his income is generated from gambling. That begs the question: how much income does he make? According to his Reddit session, he made $400,000 in 2011 (though he expected to make $280,000). How does he do it?

In his own words:

In general, I bet single games and their derivatives, rather than futures bets (say, Manchester United wins in a season, or New York Yankees runs scored in a season).

To keep it simple, there are two reasons I bet on games that return positive bankroll growth (+EG):
1) Steam plays. These make up a significant amount of my bets. You can think of this as one-sided arbitrage, where someone buys cheeseburgers from the McDonalds down the street at 90 cents and sells them at the McDonalds up the street at $1 for a guaranteed profit of 10 cents. The assumptions are that there exists an unlimited amount of burgers to be bought/sold on both sides; this is a true arbitrage and obviously cannot exist for very long.
Now think of it this way: The correct “market price” for a Yankees game is -120 (meaning I have to put up $120 to win $100; I’m a “favorite”) and the other side of the same game is +110 (put up $100 and you win $110; you’d be an underdog). Let’s just assume that -120/+110 is priced perfectly from an Economics standpoint, so a bet that has $0 of positive expectation is something close to -115. If I bet $1,000,000 on a line at a sportsbook that is -115 1,000,000 times, I expect to win/lose $0 (though there will be variance). So, if I can find a line better than -115, I’m making money by betting this line.
They call these “steam plays” because a book with a lot of liquidity for a given market will generally be close to the “market price” for a bet, and if they move their line in either direction, you have time to bet it at another book that is too slow to move their lines. Do this enough and it builds up “steam,” and usually a curt conversation with the head linesmaker at the book you are pillaging.
2) Handicapping. This is where you build a model that takes all sorts of inputs (weather, batting stats, pitcher are all simple variables) and evalutes a fair betting line – the “market price.” If you can calculate the market price better than the big books, you stand to beat opening lines for a fair amount of money. This is obviously quite hard, since the largest books employ lots of geniuses to create tough to beat lines. However, it’s not impossible. Right now, we have a model that has beaten MLB games and derivatives for a pretty large sum over the last 3 years.

That’s an informed answer and it’s clear this guy knows his stuff.

Some other evidence that AdvantageGambler is legit:

The entire thread is certainly worth a read. Based on his extremely informed answers, we think AdvantageGambler is indeed one of a very rare breed – he’s a successful professional gambler. Of course, we can’t be certain that his self-reported numbers ($400k a year and $900K at Pinnacle) aren’t inflated but he talks the talk of an educated, successful gambler.