Aaron Nola: Worlds of Potential

Heading into the 2017 season, we here at Crashburn Alley strive to update you on a specific storyline regarding many of the returning staples from last season’s roster. Today is starting pitcher Aaron Nola.

A lot of what I said in my season preview for Jerad Eickhoff could be repeated for Aaron Nola. He’s got the stellar curveball, so-so fastball, and not good changeup. Nola both strikes out and walks slightly more hitters, which gives both players near identical career K/BB rates just below 4.00. However, Nola has allowed more home runs per fly ball, and he just came off a season with a near-5 ERA.

Based on that paragraph alone, you might conclude that Eickhoff is the better pitcher right now, and you might be right, but that misses three important pieces of information about Nola that set him apart from his rotation-mate:

  • Due to his sinking fastball, Nola had a 55% ground ball rate (GB%) in 2016, compared to Eickhoff’s 41%. The league average is about 45%.
  • Nola had a strand rate (LOB%) of just 60% last year, while Eickhoff’s 76% was just above the league average of 73%.
  • Nola has dealt with injuries that may have affected his effectiveness.

When it comes to balls in play, ground balls are the ideal outcome for a pitcher. They very rarely go for extra bases (ISO: 0.020), and therefore, they have the lowest wOBA against of the three batted ball types (just .220). And even this undersells the value of ground balls, because they’re the batted ball type that is most likely to produce a double play. Nola’s ground ball rate ranked eighth in baseball last year among pitchers who threw at least 100 innings last year.

As for strand rate, I’ll let the FanGraphs Glossary take this one:

Most pitchers have LOB%s around league average (which is approximately 70-72%, depending upon the season), and pitchers that deviate from that average tend to see their numbers regress towards average in the future. In other words, if you see a pitcher with a 60 LOB%, they are letting lots of runners score so their ERA will be high, but the odds are that they will strand more runners in the future and lower their ERA.FanGraphs Glossary

In other, other words, strand rate is a fluky statistic that is likely to revert to league average for Nola this year. That doesn’t tell the whole story, as there are some extenuating circumstances that cause certain pitchers to struggle with runners on base. For instance, some pitchers may struggle out of the stretch with mechanics, but Nola hasn’t shown that consistently, as his strand rates in the minors and in his first MLB season have never been below 77%.

All of this is not to denigrate Eickhoff, as he’s shown himself to be an above average big league starter. It’s just to say that Nola has all the tools to be even better than his fellow righty, and he pitched at an ace level through the beginning of June. However, in his last 8 starts, Nola struggled mightily and was eventually shut down for the season with an elbow injury. It’s possible that he was pitching through injury towards the end of the season, and the statistics bear that out, though it should be noted that both Nola and the Phillies denied that he had been pitching through pain. Compare his first 12 starts with his last 8:

Whether or not he was injured, it’s clear that Aaron Nola has the potential to be a top-of-the-rotation starter. No qualified starters produced a K% greater than 27% and a BB% below 5% in 2016. The only pitcher to do that over 80 or more innings is Clayton Kershaw. And only three qualified starters produced a K-BB% of greater than the 22.4% Nola accrued in his first 12 starts: the late Jose Fernandez (26.9%), Max Scherzer (25.3%), and Noah Syndergaard (23.5%). Oh, and Nola had a higher GB% than all three of them. Simply put, for his first 12 starts last season, Nola was one of the best pitchers in baseball. The only thing separating him from the upper echelon of MLB pitchers is his durability.

Leave a Reply


This site uses Akismet to reduce spam. Learn how your comment data is processed.


  1. Steve

    March 22, 2017 01:36 PM

    How much does it deter the rebuild if Nola never gets past the injury? Eickhoff was essentially a lottery ticket that hit, VV has great stuff but may ultimately be a RP. There are still a lot of question marks surrounding this young team, and fortunately they have the reasources to buy at least one top of the rotation arm, but I feel like Nola was always thought of as the one slam drunk SP to stabilize the rotation through the rebuild.

    • Michael Schickling

      March 22, 2017 03:04 PM

      Well pitching is super fickle in general, but the Phillies system’s strength is young pitching depth. If Nola never gets past the injury, and VV is a reliever, then we’d hope that we can hit on Jake Thompson or Alec Asher or Adam Morgan or Zach Eflin or our various prospects like Sixto Sanchez or Kilome or Medina or Garcia.

      If none of those hit, the Phillies certainly could sign a top of the rotation starter, but they’re going to need a couple of those players to turn into mid-rotation starters if they really want to compete.

      • Ed

        March 23, 2017 02:12 PM

        Nola was considered a mid rotation guy when he was drafted. Nothing much more than that he was just advanced and could move quickly through the system to help the major league club fast. His mechanics have always given cause for concern.

      • Michael Schickling

        March 23, 2017 06:18 PM


        Its true that Nola was considered a mid-rotation starter coming out of college but the scouting report changed on him since he was drafted. See the description of Nola on FanGraphs:

        But plus command and plus movement on a three-pitch arsenal should be enough to make him as good as his peripherals suggested he should be last year. If he’s healthy, expect numbers commensurate with a fantasy number two. Any increase in velocity could push him to ace status.

  2. Major Malfunction

    March 22, 2017 02:15 PM

    If Nola pitches somewhere between last year’s 1st half and 2nd half personas, that’s certainly getting the job done for a 23 year old. Only his level of brittleness can hold him back at this point.

  3. Romus

    March 22, 2017 02:45 PM

    This spring Nola’s FB velo has been around the 91/93T94 range.
    The last two season according to Fangraphs his FB velo was less than 91.
    It, however, would really would be great if Nola eventually becomes the TOR the Phillies could count on.

    • Ed

      March 23, 2017 02:14 PM

      He’s never going to be TOR. Hate to say it.

  4. Steve

    March 22, 2017 04:26 PM

    I still don’t believe he’ll ever be durable enough to last a full season.

    It’s just the way he throws imo.. his arm can’t sustain that type of throwing long term, no stats etc will ever sell me on it.

    Go try and throw a ball with his arm angle motion etc.. sure it produces a lot of movement but at the cost of his joints/ligaments etc…

    He’ll be washed out by 29 if he makes it that long without having to reinvent himself imo/.02

    Sure i love watching him fan batters but i just don’t think he truly has it to last as a 1/2/3 guy in a rotation.. for more then a few years before his arm falls off

    • Michael Schickling

      March 22, 2017 10:35 PM

      I’m no scout, but based on what I’ve read, Nola’s delivery is considered clean, which is what gives him his great command. Yes, his arm slot is low, but that’s not exceedingly rare. I’ll defer to the scouts on this one if presented with some evidence, but I don’t see any glaring red flags in his delivery.

      • Chris S

        March 23, 2017 09:55 AM

        In addition Nola is double-jointed which is part of why he can throw the way he does. He was injured once and the injury didn’t require surgery, but now he is an injury concern? Come on, you have to give him a few more seasons before you can definitely say whether he is an injury concern or not. Cole Hamels was an “injury concern” when he first came up and now he is one of the most durable starting pitchers of the last decade.

      • Ed

        March 23, 2017 02:17 PM

        What? Clean? Never heard that one. Look, pitching is an unnatural event that puts tremendous strain on the shoulder and elbow in particular. Nola is not a particularly smooth pitcher and his low arm slot is great for deception, but puts even more stain on the elbow.

Next ArticleHector Neris: Building the Next Bullpen