This is my attempt at generating a system to beat MLB lines and a brief explanation as to why it is possible.
Inefficient statistical analysis
The FIRST reason is that baseball is a sport which is designed brilliantly for statistical analysis. It is a series of set plays which can be recorded, understood and presented statistically with great ease. Stats have always been a huge part of baseball. Herein lies the 'beatability' of MLB lines.
Historically, the stats which people have considered in assessing how could a baseballer is have been:
For batters - Batting Average (the ratio between 'hits' and 'outs' made by a batter), Home Runs, RBIs (the number of runners a batter is responsible personally for causing to score) and Stolen Bases.
For pitchers - Wins (the number of games in which a pitcher was pitching which resulted in his team winning), ERA (the number of runs given up by a pitcher, per 9 innings) and Strikeouts.
In recent years, though, these stats have come under great critical analysis from a new breed of statisticians who have proved their uselessness in assessing the quality of a baseballer and their predictive value for future success. They call this "sabermetrics". For those interested further, check out fangraphs.com.
New statistics like wOBA, FIP, xFIP have come along, recognising the luck factor associate with many of the traditional stats and seeking to 'strip back' those factors.
Vegas lines are heavily influenced by the starting pitcher, as they should be...it is the single most determinative factor in who wins any individual baseball game. It is, however, an area in which there are often weaknesses in the statistical analysis. ERA and Wins are used, where xFIP is a much better predictive factor.
The SECOND reason is that baseball is a sport which is subject to huge variation. To give you an idea, baseball teams play 162 games a year. Each year, the best two or three teams (out of 30) will win 100 games. That means the BEST teams will lose 60 or so games a year; 37% of their games.
The trouble is that people like to find patterns, it's human nature. We decide a team is better than the other, and say they're going to win. But the problem is that baseball is a hugely random game. Underdogs, therefore, become an undervalued proposition. Check out this link MLB Betting 101 | AccuScore for a look at the 2006 season. Simply backing the underdog in every match that season would have seen you +42 units.
I intend to use a few baseball predictor services (Accuscore from ESPN, as well as Fangraphs' own), combine it with some research into potentially under/overvalued Starting Pitchers and find good spots to get some money on.
First picks start tonight, follow me if you fancy it!