By the numbers: How Blue Jays bullpen has thrived in 2020

On opening day, the Toronto Blue Jays bullpen could best be described as thin and unproven beyond closer Ken Giles.

An off-season waiver claim (Anthony Bass), a minor-league free agent (A.J. Cole), and a pitcher who spent the previous four seasons in Japan (Rafael Dolis) were Giles’ set-up men. Wilmer Font and Sam Gaviglio -- veteran journeymen coming off high-usage, middling-result seasons -- were positioned to face leverage.

Jordan Romano carried a 7.63 ERA from his rookie season; Thomas Hatch had never pitched above double-A; Shun Yamaguchi, a 33-year-old veteran of 14 NPB seasons, was an utter wild card in his first MLB campaign. Long-man Jacob Waguespack and 30-year-old rookie Brian Moran rounded out a highly uncertain group.

On just the second day of the season, a lead was blown in the eighth. The day following, Giles was lost long-term to a forearm injury. It did not look promising.

But then a funny thing happened. Romano was a revelation, thriving in the high-leverage role Giles vacated. Dolis took full advantage of a league that hadn’t seen him in four years, while Bass made everyone wonder what the Seattle Mariners were thinking putting him on waivers in the first place. Cole allowed only two earned runs over his first 17 appearances, while Yamaguchi settled in and started mowing down hitters after a couple early-season, extra-inning hiccups.

Meanwhile, converted starters Hatch, Ryan Borucki, Anthony Kay and Julian Merryweather flourished in new roles, lessening the need for Gaviglio -- who was released -- and Font -- who’s on the injured list -- to face leverage at all. Same for Waguespack, who has yo-yoed between the club’s alternate training site and low MLB leverage, and Moran, who was deemed expendable and jettisoned on waivers.

Now, Toronto’s bullpen enters the final two weeks of the season as one of the best in baseball, boasting a 3.66 ERA -- third-best in the AL and fifth across MLB. Adjust for league and park factors, as FanGraphs’ ERA- does, and the Blue Jays still have a top-five group at 18 per cent better than league average. Having received a collective 3.1 wins above replacement from its relievers, Toronto is tied with the Oakland Athletics for the MLB-lead in bullpen impact.

And it’s of particular value to this club -- one that has been more reticent than most to allow its starters to take a third trip through the opposition batting order. No Blue Jays starter has thrown a pitch in the seventh inning this season. Only two teams have used their bullpens more than the Blue Jays, who have relied on relievers to pitch 209 of the club’s 407.2 innings -- a 51 per cent share.

“They absolutely have dominated,” said Giles when he finally returned from injury over the weekend. “Overall, our group of guys has been phenomenal.”

It has. And the Blue Jays will need that to continue as they near the post-season, a time when reliable relief is more important than ever. Let’s take a closer look at how the Blue Jays bullpen has done it -- and where it might go from here.

Loving Leverage

It doesn’t only feel like the Blue Jays have played a far more stressful season than the rest of MLB -- it’s reality. Of the club’s 46 games played, an MLB-high 22 have been decided by one run. Eight others have been decided by two. Toronto’s 11 extra-inning games also lead MLB. No other team has played more than eight -- and 23 teams have played fewer than six.

All those tight games have produced a wealth of high-leverage situations for Toronto’s relievers to pitch in -- and not always in late innings. FanGraphs offers several Leverage Index measures that attempt to quantify just that. And, naturally, the Blue Jays bullpen leads MLB in every single one of them.

Blue Jays bullpen leverage faced (average is 1)

Four Blue Jays -- Romano, Bass, Dolis and Cole -- are within MLB’s top-36 relievers in average leverage faced for all game events. Six -- add Merryweather and Hatch to the previous list -- are within the top-38 in average leverage faced upon entering a game. Of all the stats in this article, these may be the most telling as to how unlikely and impressive the success of this group has been.

Blue Jays relievers -- some of them with little-to-no major-league experience, some of them converted starters in new roles, some of them pitching in a new league on a new continent, some of them coming off waivers and minor-league deals, essentially all of them unproven in some way -- have pitched with a minuscule margin for error all season. And they’ve excelled in spite of it.

To that end, Toronto hasn’t only received strong play from its bullpen -- it’s needed it. If the group had been even league average, allowing an extra run here and there, several of Toronto’s tight wins become tight losses. And, suddenly, the club is looking up at the AL playoff picture rather than competing in the middle of it.

Sheer Velocity

MLB’s average fastball velocity has climbed steadily each season since 2008. Back then, throwing 94 m.p.h as a reliever was exceptional. Today, it’s the norm.

But the Blue Jays organization has been slow to keep up with the trend. In each of the last two seasons, the club’s relievers have ranked No. 24 across MLB with average fastball velocities (including four-seamers, two-seamers, cutters and sinkers) below 93 m.p.h. And in 2017, the club finished dead last at 91.9 mph.

This season, that’s changed. The Blue Jays have the seventh-hardest throwing bullpen across MLB with an average fastball velocity of 93.8 mph.

MLB’s hardest-throwing bullpens

Leading the way are Merryweather (97 mph average fastball velocity) and Romano (96.5). One-time starters Hatch (95.4) and Borucki (94.8) are also contributing as their stuff plays up in relief. And a return to form from Giles -- his velocity is typically in the high 90s but has been reduced this season as he’s battled injury -- ought to help pull the average up even further.

And all that heat comes in many varieties. Merryweather and Romano’s four-seamers are simply overpowering. Borucki’s two-seamer features above-average horizontal movement, keeping it off the barrels of bats. Hatch throws a high-spin fastball that hitters consistently swing underneath, while Dolis throws a 94.5 mph sinker they swing above.

It’s all come together to give manager Charlie Montoyo more capable weapons to deploy in late innings when he needs strikeouts or groundballs in big spots. And after years of watching hard-throwers spill out of division rival bullpens in New York and Tampa Bay, the Blue Jays have finally caught up to the trend.

Keeping The Ball In The Yard

This one’s either encouraging or troubling, depending on your perspective. To this point in the season, Toronto’s bullpen has been among the best at limiting home runs, allowing only 18 through 209 innings. That’s the fourth-least allowed in MLB. Consider that the playoff-bound Philadelphia Phillies bullpen has allowed nearly twice that amount (34) in only two-thirds of the innings (146).

MLB bullpen home run rates

In an offensive environment in which the rate of home runs per nine innings played -- 1.35 this year; 1.4 in 2019 -- is the highest it’s ever been in the history of the game, Toronto’s success at limiting long balls is definitely a good thing. But it’s also concerning, because home runs rates are extremely susceptible to luck. The one reliable way to decrease the amount of home runs hit is to give up fewer fly balls. But Toronto’s bullpen fly ball rate -- 38 per cent -- is the 11th highest across MLB.

It’s why Blue Jays relievers have the lowest home run to fly ball rate in baseball at 8.5 per cent. That suggests some good fortune has been involved. And while it’s not always the case, a low HR/FB rate can sometimes portend a coming correction in the number of fly balls that end up carrying over the fence.

The good news is Blue Jays relievers have been very effective at limiting hard contact this season, allowing a hard-hit rate of 33.3 per cent that sits among the top-10 teams in baseball. And per MLB’s StatCast, only 5.4 per cent of the balls in play allowed by Toronto’s bullpen have been classified as a barrel -- the third-best mark in the game. Limit that kind of contact and you’ll generally limit home runs.

Still, there could be regression ahead, particularly with the Blue Jays playing series this week at Yankee Stadium and Citizens Bank Park, each regularly among MLB’s top home-run hitting environments. And for as strong as Toronto’s bullpen has been, it does surrender its fair share of free passes, with an 11.7 per cent walk rate -- tied for fifth in MLB.

That means that if some of those fly balls do start to leave the yard, there's a strong possibility they’ll plate more than one run. We’ll see. The good fortune could certainly continue. Either way, it’s one factor to keep an eye one as this unexpectedly thriving Blue Jays bullpen tries to keep its success rolling into the post-season.