Bullpen Strength is Everything in 2021

Here’s a hot take – the starting pitcher is no longer the most important aspect of handicapping MLB baseball.

What!? That’s blasphemy!

No it’s not, you gotta stay up to date on things, bro.

MLB Starters are Fading

In the mid-70s, the average MLB start length was over 6 and a half innings. By 1980, the average start length was about 6 and one-third innings.

2011 was the last season in which starting pitchers averaged over 6 innings per start. In 2019, starting pitchers averaged 5.16 innings per start – the lowest mark in the history of baseball.

Take a look at this chart and note the clear downward trend of MLB starter innings per game. 2020 is an outlier. The lack of a traditional Spring Training last year led to many pitchers showing up out of shape. Managers became even more conservative than usual with those precious pitching arms.

With starters throwing only half of the game and bullpens tasked with getting teams through the most important innings of the game there is a strong argument that bullpen handicapping is far more important than starting pitching handicapping.

This phenomenon is not just true for the middle-of-the-rotation guys – bona fide aces are not pitching deep in the games either.

Gone are the days of aces routinely giving their team 8 or 9 innings of work. The Major League leader in complete games these days typically only notches 3 or 4. The league leader in shutouts is lucky to reach 2.

Once again, we need to take the 2020 numbers in the chart with a grain of salt. Because it was only a 60-game season I extrapolated the data out to a full 162-game schedule. As you can see we were on a fast pace of complete game shutouts in the shortened season. Removing this outlier from the data however leaves you with a very strong downward trend – just like the innings per start chart.

What caused the concentration of complete games and shutouts to increase in 2020? My hypothesis is that while most pitchers did not train as hard during quarantine as they would in a normal year, some of the true competitors in the league trained even harder than normal.

This led to a select few MLB pitchers being in the best shape of their careers and lasting even longer in games. On top of that, managers knew that some of the arms in their bullpen were not as effective as normal and leaving the starter in seemed like a great option.

The reason that starters are not lasting as long in games is twofold.

Modern “science” suggests that babying pitchers’ arms is best for their longevity. Most MLB managers have bought into this way of thinking.

As someone with a certification in strength and conditioning – I personally disagree with this mantra. Pitching requires the use of many muscles – both big and small – in the arm, shoulder, chest, and back. Building strength in these muscles is the best way to increase both pitching performance and durability.

In order to increase muscle strength you must work these muscles to exhaustion and max them out once in a while. By babying your pitching muscles you are not building strength, hampering performance, and leaving yourself more vulnerable to injury.

New school managers will say, “I told you so,” every time a pitcher suffers a season-ending arm injury – not realizing that the rate of major arm injuries and Tommy John surgeries have skyrocketed in the past 15 years. Hmm … this is right around the same time that managers began babying their pitchers. Coincidence?

The other reason for shorter starts in the MLB is much more quantifiable – pitchers are throwing harder now than they did in years past – using more of their energy with each pitch and thus being unable to pitch deeper into games.

I’m going to use the best baseball video game on the market – MLB The Show – as my example here. When pitching in that game I love to use meter pitching. Meter pitching allows you to select the power the pitcher puts into his pitch.

Stopping the meter low in the power zone will result in a mediocre breaking pitch or a meaty fastball. Sometimes this is useful if you’re trying to throw a get-me-over curveball on the first pitch of an at-bat or put a four-seamer in the middle third in a 3-0 count. Maxing out the power meter will result in your pitcher throwing the hardest fastball he can or putting the most break on a curveball or slider that he can.

Obviously, your pitcher will tire much faster if you are constantly throwing maxed-out pitches. In the old days (circa 2010), managers preferred to have their starting pitchers pace themselves in order to last deeper into the game and log 7, 8, or even a full 9 innings. With the prevalence of good bullpen arms, managers have realized that turning to the pen early isn’t necessarily a bad thing and so having your starter throw as hard as he can right away will be more effective.

Take a look at this chart of average fastball velocity in the MLB since 2011. Relievers have always thrown a little bit harder than starters because they can go all out, knowing they are only in the game for an inning or two. Notice the strong upward trend of both starter and reliever fastball velocity over the last 11 years.

Throwing hard fastballs does not come without a couple of consequences – the first being less durability, which we have well documented. The other downside of throwing harder is that hitters can hit the ball harder. It’s simple physics – the faster the ball comes in the faster it will leave.

Average exit velocity off the bat is a product of both pitching velocity and hitter ability. StatCast is a system of sensors installed in all 30 MLB stadiums since 2015 which can track stats like exit velocity off the bat, running speed in the outfield, or spin rate on pitches.

We only have about 6 years of data but that is enough to notice a pretty solid upward trend in average exit velocity. It is no surprise that exit velocities are increasing as fastball velocity is increasing.

A change in hitting style in the MLB is also responsible for more hard-hit balls. Coaches used to stress contact and putting the ball in play above power – figuring that strikeouts are the worst possible outcome of an at-bat.

That way of thinking has been altered due to advanced metrics which indicate that hitting for power and going for the three-run homer can be a more effective approach than stringing together singles.

Hitters with high strikeout rates used to have a hard time finding a spot in the lineup. Managers now have no problem with penciling in all-or-nothing guys who either hit a 500-foot homer or strike out on three pitches in the dirt.

2-strike swings are slowly becoming extinct in baseball. When I was young we were told to choke up with two strikes, widen our feet, and just try to put the ball in play. Hitters are now receiving the green light to continue swinging for the fences even after falling behind.

Because pitchers are throwing harder and hitters are swinging harder, there are many more hard-hit balls now than there were even just 5 years ago in the majors. Taking a look at the StatCast data on hard-hit ball percentage since 2015 shows a sharp increase each year.

Which 2021 Bullpens are Reliable?

All this data is to show that looking only at starting pitching means you are analyzing half or even less than half of the game in many cases. Bullpens receive plenty of mound time and must be accounted for in any handicapping endeavor.

So which teams have the best bullpens in 2021 and which managers elect to use their bullpens the most? Great! Now you’re asking the right questions. Let’s take a look.

Below are the top-five bullpens in baseball ranked by their collective ERA. At the very bottom is the last-place team in bullpen ERA this year – the Cincinnati Reds – just to show the range of ERAs that exist in the league.

It’s no surprise that the top couple of bullpens in baseball both reside in the National League. The National League still makes their pitchers bat which causes National League ERAs to be about a full run lower than their American League counterparts. Surprisingly, the next several spots are held by American League teams which speaks to their effectiveness. The next National League teams on the list are the Giants and Mets tied in 7th place at 3.55.

The Cincinnati Reds have an absolutely awful bullpen – meaning that more runs are scored during the 6th, 7th, 8th, and 9th innings of Reds games than the first five. See? Handicapping just the Reds starters will lead to some horribly inaccurate predictions.

What about garbage time? Do we need to account for that? Sometimes a team will be up 10 runs and will put in a minor leaguer or a position player in a mop up role. Doesn’t this inflate bullpen ERAs?

True. Although team ERA is a good indication of bullpen strength it is not the whole story. Some teams tend to play down to their competition and will not pitch with the same intensity with a five-run lead as they would with a one-run lead.

In order to see which teams preserve leads and which choke – let’s look at which bullpens have blown the most games this year. This is the bottom-five teams in terms of bullpen losses with the Oakland A’s thrown in at the bottom as the team with the least bullpen losses to show the range that exists.

There’s no surprise that there are many bad teams on this list. The Twins, Rangers, and Diamondbacks are all last place teams with a collective record of 69-122. It is amazing that the Houston Astros have a winning record of 36-27 and are in second place in the AL West with as many times as their bullpen has blown the lead this year.

The 2021 Astros remind me of the Detroit Tigers from the mid 2010s when the team had amazing starters and a Murderers Row of a lineup but never had a bullpen to be confident in. This held the team back – especially in the playoffs – and is the main reason why the Detroit Tigers have not won a World Series since 1984.

Not shockingly, the Oakland A’s lead their division with a record of 39-27.

Now onto a rather interesting stat that I’m not exactly sure how to interpret – I’ll leave it up to the reader. This next chart is the top-five teams in the league ranked by average innings pitched by relievers in each game.

Some may come to the conclusion that having relievers throw a lot of innings per game is a bad thing because it means your starters are not making it deep into games. Others can conclude this is a good thing so long as it is done intentionally and not out of necessity.

For example, the Tampa Bay Rays lead the league in most innings per game by relievers but also have the lowest ERA of any bullpen in the American League – showing that manager Kevin Cash intentionally goes to his bullpen early because he knows it is so strong.

Here are the top five along with the bullpen that receives the least mound time in the Majors to display the range.

The Rays, Padres, and Cubs all possess excellent bullpens and the reason for so much reliever usage is obviously that the manager feels more comfortable turning to the pen rather than keeping their starter in for a third time through the lineup.

The Orioles, Angels, and Mets do not strike fear into their opponents hearts with their bullpens. The reason these pens receive so much mound time is pretty simple – their starting pitching stinks.

Remember boppers, bullpens are an increasingly prevalent part of Major League baseball and must be factored into your projections.

Do not bet on 2021 MLB games with a 2002 mindset. Do your research and take advantage of soft lines. See you on top!