On a rainy Sunday afternoon at Citizens Bank Park, you could almost feel it coming. The dread, creeping along like the storm clouds blotting out the midday sun, reminding you that something bad was going to happen. Like clockwork, the Phillies lost in heartbreaking fashion to the indomitable Mets, blowing two saves, and dropping two of three to their division rival.
The team is 4-6 in their last ten games and after Sunday’s loss, have slipped to the third N.L. Wildcard spot, a half game behind San Diego and just one and a half ahead of Milwaukee. Although Bryce Harper is set to return in a matter of weeks and the ballclub faces team’s with a losing record in their next 19 games – prompting Baseball Reference and FanGraphs to place their postseason odds at 87.8% and 73.1% respectively – the road to October baseball still remains as tough as ever. With reliever Corey Knebel out for the year and closer Seranthony Dominguez placed on the 15-day IL, the club entered into Sunday’s matchup with a short-staffed bullpen. The result wasn’t pretty.
The injuries to the bullpen and the dropping of consecutive series to the Mets are almost enough to make you question whether or not the Phillies, at 66-55 – better than they’ve been in years – are actually destined for the playoffs. Will this summer’s torrid streak under interim manager Rob Thomson actually lead to the quenching of an 11-year playoff drought or was this magnificent run destined to fail come September?
While the Phillies fate will be determined by an amalgamation of factors, few are more important than starting pitcher Aaron Nola’s performance come September. After weathering a rocky 2021, Nola has bounced back to become one of the top pitchers in baseball and a dark horse Cy Young candidate. Over 24 starts, Nola has an 8-10 record and a 3.25 ERA. Amongst N.L. pitchers, he is 2nd in innings pitched (157.2), 3rd in WAR (4.6), 3rd in FIP (2.77), 3rd in WHIP (0.958), 3rd in total strikeouts (174), and 5th in strikeouts per 9 innings (9.932). He also leads the N.L. in Walks per 9 innings and Strikeout to Walk Ratio. He has been the Aaron Nola of old, a master of control, making opposing batters look foolish with his signature knuckle-curve and routinely pitching deep into games. He’s done everything possible to shuck last year’s label of inefficient strikeout king and could be argued for as the team’s best pitcher next to the dominant Zach Wheeler.
Yet still, a single word threatens to cast a shadow of doubt over his stellar season: September. That nagging uncertainty crept into the minds of Phillies fans on Friday night, when in a battle against Jacob DeGrom, Nola went just 5 innings, surrendering five earned runs over eight hits en route to yet another loss to the Mets. Was this the beginning of the end for Nola’s season?
Throughout his career, the month of September – including the last regular season games of October – has been troublesome for Nola. In 2021, his ERA jumped from 4.28 in August to 6.19 in September/October. In 2020, it went from 2.35 in August to 3.57, costing him a chance at the Cy Young Award in the COVID-19 shortened season. In 2019, it ballooned from 2.52 to 6.51 as opposing hitter’s batting averages jumped nearly 100 points. And in an otherwise excellent 2018, in which he finished 3rd in the Cy Young voting, Nola allowed nine home runs in September – just as many as he had given up the entire season.
So what gives? What is it about September that continuously turns him from a strong pitcher to liability on the mound?
Although Nola, a Louisiana native, does have a penchant for pitching in warmer weather – a career 2.96 ERA in August, the lowest of any month – the drop in temperature come September cannot possibly be the main contributor to his decreased performance. After all, from August to September, the average high only drops from 85 to 78 degrees Fahrenheit and the average low from 68 to 60 degrees Fahrenheit. Moreover, Nola’s career ERA jumps from 3.05 in May to 4.42 in June, just as the summer months begin to heat up.
Unfortunately, the answer to Nola’s dilemma isn’t clear cut – a number of factors likely contribute to his September sorrows, the most obvious one being fatigue. Nola is a control pitcher, dependent on precise location and movement of his pitches – he uses his low-nineties 4-seam fastball and sinker to set up his off-speed pitches, instead of being bailed out by a 100mph heater. While Nola doesn’t typically see any losses in velocity, spin rate, average release extension, vertical or horizontal break, or spin rate from August to September, he does see the effectiveness of nearly all of his pitches decline. Take for example his knuckle-curve, which from August to September of 2021 went from .171 BAA, 86.1-92.8mph average exit velocity, and 40.8-30.9% whiff rate. Additionally from 2019-2021, his knuckle-curve caught opposing batter’s barrels more as well.
While his pitches aren’t in the zone any more than they typically are during the previous months, Nola’s command seems to wane come September. His WHIP and walks allowed have risen every year from 2018 in conjunction with the higher exit velocities and batting averages against his pitches. Simply put, the less he is able to command his pitches – most notably his 4-seamer and sinker – the less he is able to fool opposing batters. As devastating as his off-speed pitches can be, they aren’t much use when he can’t set them up with a well-placed fastball.
So what does this mean for the Phillies chances this September? Is Nola bound to fall apart, too fatigued to finish the year?
Not exactly. Although Nola is 2nd in the N.L. in innings pitched this year, his mark of 157.2 IP entering September is his second lowest since 2018. In both 2018 and 2019, Nola had pitched over 170 innings prior to September, ending with 212.1 and 202.1 at year’s end respectively. (While he pitched only 148.2 innings prior to September in 2021, the fatigue element seems less responsible for his poor performance than the fact that he struggled all year long). The upside for Nola and the Phillies this year is that hopefully, with his limited innings he can stay fresh and effective when it counts.