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MLB Betting Tips: How to Make Money Handicapping Bullpens


It used to be a badge of honor for a pitcher to throw a complete game. Back in 1985, Bert Blyleven led the American League with a whopping 24 complete games. Dwight Gooden threw 16 of them to lead the National League. Fast forward to 2018, where no pitcher had more than two complete games for the season. That’s right, not a single starting pitcher hurled more than two complete games last season. This year won’t be much different. Why the drastic change in the workload for starting pitchers? It took a long time, but MLB organizations have finally learned through analytics that it doesn’t pay off to have a starting pitcher go through the order multiple times. The numbers make that very clear. As a result, bullpens have become an increasingly important part of every team. 

Last season, MLB bullpens logged over 17,400 innings. That was the highest mark ever and it’s likely to increase again in 2019. As bettors, that means more weight has to be given to the guys in the pen than ever. There are several schools of thought on how to effectively handicap bullpens. The wrong way to handicap a bullpen is to look at the overall numbers for the season. Let’s say the Atlanta Braves have a bullpen ERA (or insert your favorite peripheral such as xFIP or SIERA) of 4.29 for the season on July 14th. If you’re using that number to come up with an estimate of how many runs the Braves’ bullpen are going to allow for a given game, you’ll likely arrive at the wrong answer. Bullpens are extremely fluid throughout the course of the season. Guys that struggle early on in the season get demoted to the minor leagues. Injuries frequently occurespecially considering how hard most guys are throwing out of the pen these days. New arms emerge from the minors or via trade. There is constant shuffling in bullpen roles as well. Over half of the closers at the beginning of the season lose their jobs by the All-Star break.  

The bottom line – what a bullpen looks like today is usually vastly different than what it looked like a few months ago (or even a few weeks ago in some cases). In order to properly handicap a bullpen, you have to take into account the composition of the bullpen right now. Who are the most important guys and what are their roles? The pitcher that had a 7.50 ERA and was demoted two months ago is no longer relevant. He certainly impacts the overall bullpen ERA for the season, but that shouldn’t concern you. Conversely, there are likely a couple of guys in the bullpen that have recently emerged and have yet to rack up very many innings. They might be more important than anyone. 

Bullpen availability for a particular game is another important aspect of the handicap. If a team’s closer has pitched three straight days, he’s irrelevant to the handicap for today because he’s not going to be used unless the game goes well into extra innings. You should only be concerned with the pitchers who are available. Knowing the patterns of bullpen usage by each manager goes a long way in determining who is likely to pitch in a particular game. Some managers will rarely utilize a bullpen arm three days in a row, while otherwork their pens to death without thinking about long-term repercussions. Study these patterns closely. Paying attention to pitch counts is vital as well. Most relievers are going to be out of commission once they throw over 35 pitches the day before (there are exceptions of course). On the other hand, if an elite bullpen arm hasn’t been used for five days, it’s likely the manager is going to try and get him some work to keep him sharp regardless of the score and situation. 

Once you have a firm grasp of the relievers who are available, it’s time to start thinking in terms of probabilities. I like to assess the probability, in terms of a percentage, that each pitcher gets into the game. Those probabilities allow you to essentially weight their expected runs allowed properly. You must also take into account how many outs they are likely to be asked to record by the manager since this also plays into the overall weighting. Most handicappers won’t go to this level of detail when handicapping a baseball game. And for that reason, you can find some huge edges by simply handicapping bullpens each day. There are many situations where two bullpens who are relatively similar in terms of effectiveness for the season overall, face off against one another but Team A has a huge advantage over Team B just based on the expected pen usage for that game. Pay attention to bullpens each day and you’ll uncover those instances. They are rarely taken into account in the opening lines by sportsbooks and will lead to some fantastic wagers. Even if you don’t get heavy into the math, it’s oftentimes very easy to spot a vulnerable bullpen situation. 

So how do we go about things in the beginning of the season, before we have any real numbers to work with for a team’s bullpen? Projections are the first place to start. You will have much more success in estimating runs allowed for bullpens using projections than you will using last year’s numbers. Bullpen numbers are extremely volatile from year to year given how few innings most relievers pitch. A couple of bad outings can balloon a respectable 2.90 ERA all the way to 4.50. Projection systems do a better job of analyzing peripherals to determine the most likely outcome for a given pitcher. That being said, public projection systems are available to everyone and definitely have some major holes. It’s not easy, but creating your own set of projections can lead to more accurate forecasting once you discover the holes in public projection systems. It’s much tougher to project bullpens than it is for hitters and starting pitchers, but the payoff can be exceptional.  

The time of the year has a big impact on bullpens as well. Arm fatigue isn’t much of a factor in April and May. Relievers are still fresh and the weather isn’t too overbearing. However, once the dog days of summer are underway in July and August, you can find some incredible hidden bullpen advantages. Those advantages are diminished in September, where 40-man rosters kick in and managers can spread out the workload more easily.  

Staying on top of bullpens each day will you put you ahead of 95% of the other bettors out there. The more time you spend studying pens, the bigger your edge will likely be. It can lead to more profits on sides, totals and live betting when the games come down to the bullpens. Time to get studying! 

Eric Waz

Waz has been a successful professional sports bettor since moving to Las Vegas in 2010. His comprehensive approach to sports betting includes quantifying the impact of factors that can be difficult to evaluate (scheduling, injuries, coaching, etc.). He’s developed several cutting-edge handicapping tools that are now available at BettorIQ. Waz won the 2011 NFL Last Man Standing title ($86,000) at Station Casinos by beating out over 4,200 entrants. He has also notched 5 cashes in 7 years in the prestigious Westgate NFL Supercontest. Get on board with a true professional sports bettor with a proven track record.