My small but loyal following often sends requests that I post more frequently, and I always have the same reply: I'll write when I have a point to make. Frankly, the quality of intelligent sportswriting is generally so good nowadays that I have little to add to the discussion.
But once in awhile, someone comes along and manages to fool even the luminaries of baseball analysis into thinking he makes a legitimate point.
The comments on the original post do a pretty good job of summing up its flaws, so this won't take too long. Basically, the author took data from one year of MLB games and determined that in that year, there was little or no favorite/underdog bias in the closing lines for each game. So, if your strategy is to bet either the underdog or the favorite in all 2430 games, paying full juice, you're very unlikely to show a profit on the year. His conclusion: no betting model can be demonstrated to beat Vegas.
Needless to say, I was disappointed to learn that the repo men will soon be here for my Lexus and stock portfolio, since they were purchased with money I couldn't possibly have won over the past four years. While I wait for them to show up, though, let's bet on some baseball! I'll book your action, since the house never loses.
The home team wins about 54% of baseball games, making -117 a fair line on the home team. I'll let you take any away team on the board for +100 or any home team for -130. Unless home teams run really hot or cold, I'm going to crush you over the course of the season. Right?
Maybe, if you're a degenerate moron. But let's pretend for a minute that you're not: how would you approach this proposition? You stay away from the close games and save your money for when C.C. Sabathia is facing Livan Hernandez. Assuming you have the discipline not to wager blindly, I will go broke in no time flat even though my book is "unbeatable".
I hear you saying, "Now just a dang minute. Chris Moore is telling me that the only way to bet baseball is to back all 2430 favorites or all 2430 underdogs each season. And what if the line is close to even money and the favorite becomes the dog? Do I have to bet on both teams? HELP!"
Fortunately for the pros, nobody is holding a gun to their heads. They can lay off most games, bet only when they see an edge, and still enjoy a reasonable ROI over a large volume. 'Cause knowledge is power!
I eagerly await Chris Moore's next column, about the MIT Blackjack team and their incredible run of luck at another unbeatable game. Hopefully between then and now someone will explain to him the difference between "your" and "you're".
Postscript: The comments for these articles include extended discussions of season win over/under bets as a potentially profitable alternative to individual games. One popular data point is the 2008 Rays, who were tabbed for 85-90 wins by various forecasts. People are quoting anywhere from 72 to 74 wins as the "Vegas line".
I probably monitored this prop more closely than anyone, since I placed about forty separate wagers on the Over. The line actually opened at 68.5(!) in mid-February at BetCRIS. Within twelve hours I and other sharps had bet it up to 71.5. It grew slowly from there, eventually closing at 76.5*. Was the Over was no longer a profitable play? No, the books were drawing roughly equal action on both sides of 76.5, so they moved it no further. If I hadn't exhausted my futures budget, it would have closed at 78 instead.
mgl commented that we "will NEVER see a line like" this again. This may be true: the 2008 Rays were a perfect storm of young talent bouncing back from a season where they underperformed and got very unlucky. I may never again see a team be so underestimated heading into a season. However, I don't share his general pessimism regarding season wins lines. In 2007, the White Sox over/under was anywhere from 86.5 to 89.5 against a PECOTA forecast of 72 wins. They actually won 72 games. Why didn't this cause the 2008 bookies to open Tampa Bay at 88 wins instead of 68.5, or Seattle at 76 wins instead of 87.5? Because the sports betting market doesn't work that way. Beating these lines is tougher than it was two years ago, but things don't change that quickly.
*Some books adjust the vig on season wins lines instead of the total. At books offering a line of 73.5, the price on the over was -200 or worse.