I have to admit that when I read Colin O'Keefe's post saying that the Mariners might have "the best starting rotation in the American League" my heart got a little fluttery. James Paxton's lousy start served as a bit of a defibrillator, but then Taijuan Walker got me all tachycardic again. With Felix, Kuma, Paxton and Walker I had visions of four Aces. Maybe like the great Phillies staff that got a giant write up in the New York Times of all places.
But of course I couldn't leave myself with a vague wish, I wanted to prove that we really could have four Aces. So down the rabbit hole I went.
What's an Ace anyway?
There are a couple of ways to figure out the definition of an "Ace". Wikipedia says "an ace is the best starting pitcher on a team" which is a dumb definition because
- It means that, say, Josh Collmenter with his 3.87 FIP and 2.0 WAR was an Ace last year.
- It blows the premise of this whole piece out of the water.
Stuart Wallace defined an ace based on number of plus pitches + FIP + innings pitched at Beyond the Box Score, but he came up with only 2 aces in 2013 and neither of them was Felix, so that's a lame metric. Of course, there is already a stat built on FIP and innings pitched: Fangraphs WAR. But even if we use WAR, we still need to figure out that "ace" cutoff.
I decided that given there are 5 starters on a team, we could call an Ace someone in the top 20% of starters, whatever team he played on.
I took all the pitchers who threw at least 100 innings and had 10 or more starts in a season for the last 15 years (that's 2081 pitcher-seasons) and divided their seasons into quintiles:
| Pitcher Type | WAR Range |
| Ace | > 3.6 |
| #2 | 2.6-3.6 |
| #3 | 1.7-2.5 |
| #4 | 1.0-1.6 |
| #5 | .9 or less |
You could totally round those to the nearest .5, but I'm just using them as is.
Interestingly the 80th percentile bar actually moves around quite a bit year-to-year (3.8 in 2003, but 3.16 in 2004), but there's no trend. Since WAR is supposed to be comparable across years I chose a single cutoff and let the number of aces vary each year (31 in 2003, 21 in 2004).
Can a team really have 4 Aces?
Yes! The odds of getting 4 Aces in 5-card stud are something like 1 in 54,000, but there have already been a few four-Ace teams this millenium. Here's how the number of aces per team broke down:
| Number of Aces | Count of teams | Percent of teams |
| 0 | 173 | 38.4% |
| 1 | 184 | 40.9% |
| 2 | 68 | 15.1% |
| 3 | 22 | 4.9% |
| 4 | 3 | 0.7% |
These are the four-ace teams:
2002 Yankees
| Name | W | L | GS | IP | K/9 | BB/9 | HR/9 | ERA | FIP | WAR |
| Mike Mussina | 18 | 10 | 33 | 215.2 | 7.6 | 2 | 1.13 | 4.05 | 3.64 | 4.5 |
| David Wells | 19 | 7 | 31 | 206.1 | 5.98 | 1.96 | 0.92 | 3.75 | 3.68 | 4.4 |
| Roger Clemens | 13 | 6 | 29 | 180 | 9.6 | 3.15 | 0.9 | 4.35 | 3.30 | 4.3 |
| Andy Pettitte | 13 | 5 | 22 | 134.2 | 6.48 | 2.14 | 0.4 | 3.27 | 2.90 | 3.8 |
Won 103 games, but lost to the Angels in the ALDS.
2003 Yankees
| Name | W | L | GS | IP | K/9 | BB/9 | HR/9 | ERA | FIP | WAR |
| Mike Mussina | 17 | 8 | 31 | 214.2 | 8.18 | 1.68 | 0.88 | 3.40 | 3.09 | 6.1 |
| Andy Pettitte | 21 | 8 | 33 | 208.1 | 7.78 | 2.16 | 0.91 | 4.02 | 3.35 | 5.1 |
| Roger Clemens | 17 | 9 | 33 | 211.2 | 8.08 | 2.47 | 1.02 | 3.91 | 3.60 | 4.5 |
| David Wells | 15 | 7 | 30 | 213 | 4.27 | 0.85 | 1.01 | 4.14 | 3.94 | 3.8 |
Won 101 games, but lost to the Marlins in the World Series.
2013 Tigers
| Name | W | L | GS | IP | K/9 | BB/9 | HR/9 | ERA | FIP | WAR |
| Max Scherzer | 21 | 3 | 32 | 214.1 | 10.08 | 2.35 | 0.76 | 2.90 | 2.74 | 6 |
| Anibal Sanchez | 14 | 8 | 29 | 182 | 9.99 | 2.67 | 0.45 | 2.57 | 2.39 | 5.9 |
| Justin Verlander | 13 | 12 | 34 | 218.1 | 8.95 | 3.09 | 0.78 | 3.46 | 3.28 | 4.8 |
| Doug Fister | 14 | 9 | 32 | 208.2 | 6.86 | 1.9 | 0.6 | 3.67 | 3.26 | 4.1 |
Won 93 games, but lost to the Red Sox in the ALCS. Yes, Doug Fister was an ace after he left Seattle.
All of those teams made the playoffs, but none won the World Series. Wait, here's a team that did win it.
2001 Diamondbacks
| Name | W | L | GS | IP | K/9 | BB/9 | HR/9 | ERA | FIP | WAR |
| Randy Johnson | 21 | 6 | 34 | 249.2 | 13.41 | 2.56 | 0.68 | 2.49 | 2.13 | 10.4 |
| Curt Schilling | 22 | 6 | 35 | 256.2 | 10.27 | 1.37 | 1.3 | 2.98 | 3.11 | 7.3 |
OK, they don't really count, but that's 4 Aces in two guys. I do wonder if you are better off getting your 18 WAR from 3 or 4 starters, but I don't want to start an argument about the composition of team WAR that I'm sure to lose.
Not shown above - that famous Phillies rotation. Halladay (8.4 WAR), Lee (6.8) and Hamels (5.0) easily passed my bar, but Oswalt ended the year with 2.7 WAR.
Also, only 3 of these guys were Aces in 2011, despite what it said on the commemorative t-shirt.
Jonathan Sanchez? Really?
Isn't this supposed to be an M's blog?
Oh yeah. Back to the M's. Other than Felix, our Ace story isn't that illustrious. As you can see below, we had some dark years before Felix invented his changeup. No true aces from 2004-2008. Since then we've had Felix and even had two Aces twice. Of course we traded one of them mid-season.
| Season | Ace | W | L | GS | IP | K/9 | BB/9 | HR/9 | ERA | FIP | WAR |
| 2000 | Aaron Sele | 17 | 10 | 34 | 211.2 | 5.83 | 3.15 | 0.72 | 4.51 | 4.00 | 4.3 |
| 2001 | Freddy Garcia | 18 | 6 | 34 | 238.2 | 6.15 | 2.6 | 0.6 | 3.05 | 3.48 | 5.3 |
| 2002 | Jamie Moyer | 13 | 8 | 34 | 230.2 | 5.74 | 1.95 | 1.09 | 3.32 | 4.03 | 3.9 |
| 2003 | Jamie Moyer | 21 | 7 | 33 | 215 | 5.4 | 2.76 | 0.8 | 3.27 | 4.01 | 3.9 |
| 2009 | Felix Hernandez | 19 | 5 | 34 | 238.2 | 8.18 | 2.68 | 0.57 | 2.49 | 3.09 | 6.2 |
| 2010 | Felix Hernandez | 13 | 12 | 34 | 249.2 | 8.36 | 2.52 | 0.61 | 2.27 | 3.04 | 6.0 |
| Cliff Lee | 8 | 3 | 13 | 103.2 | 7.73 | 0.52 | 0.43 | 2.34 | 2.16 | 3.9 | |
| 2011 | Felix Hernandez | 14 | 14 | 33 | 233.2 | 8.55 | 2.58 | 0.73 | 3.47 | 3.13 | 4.9 |
| 2012 | Felix Hernandez | 13 | 9 | 33 | 232 | 8.65 | 2.17 | 0.54 | 3.06 | 2.84 | 6.2 |
| 2013 | Felix Hernandez | 12 | 10 | 31 | 204.1 | 9.51 | 2.03 | 0.66 | 3.04 | 2.61 | 5.7 |
| Hisashi Iwakuma | 14 | 6 | 33 | 219.2 | 7.58 | 1.72 | 1.02 | 2.66 | 3.44 | 3.8 | |
| 2014 | Felix Hernandez | 15 | 6 | 34 | 236 | 9.46 | 1.75 | 0.61 | 2.14 | 2.56 | 6.1 |
Now's our time, right?
Sorry to say, probably not. Let's just start with Steamer projections.
| Name | IP | K/9 | BB/9 | HR/9 | BABIP | LOB% | ERA | FIP | WAR |
| Felix Hernandez | 217 | 9.3 | 1.9 | 0.6 | 0.302 | 75.30% | 2.79 | 2.74 | 5.1 |
| Hisashi Iwakuma | 204 | 7.4 | 1.6 | 1.0 | 0.295 | 73.30% | 3.40 | 3.48 | 2.9 |
| James Paxton | 170 | 7.2 | 3.4 | 0.8 | 0.301 | 71.30% | 3.92 | 3.91 | 1.5 |
| Taijuan Walker | 130 | 8.0 | 3.3 | 0.9 | 0.298 | 71.20% | 3.98 | 3.98 | 1.2 |
| J.A. Happ | 158 | 7.6 | 3.2 | 1.1 | 0.300 | 72.00% | 4.13 | 4.14 | 1.0 |
That's not very promising. They basically see the Mariners staff as an Ace, a #2 and three #4 pitchers. ZiPS expects even less than Steamer. Steamer is put together by really smart folks, but it is more bearish on Walker and Paxton than I am, both in innings pitched and in performance. Here's my somewhat hopeful projection.
- Felix is a lock. He's an Ace.
- Iwakuma is older. It's unlikely he'll be quite back to his 2013 All-star self, which was barely Ace-worthy at 3.8 WAR. A solid #2.
- Taijuan Walker is likely to be limited to something like 180 innings. It's certainly possible to be an Ace with that number of innings (Chris Sale had 5.1 WAR in 174 innings last year), but it's pretty rare with that little experience. Our own Michael Pineda went to the All Star game in 2012, but "only" put up 3.3 WAR. Matt Harvey and Jose Fernandez were young Aces in 2013 before they both had to get a new UCL installed. Be careful what you wish for. I'll temper my hopes and guess that Walker will be a #2 this year and an Ace next.
- James Paxton is projected to take a step back this year. ZiPS and Steamer see his FIP going from 3.28 to over 3.9. But I believe in Dadgut. If he can maintain last year's stats for a full 180 innings, he's likely to deliver almost 3 WAR. Still not an Ace, but he could be a number two also.
- J.A. Happ at 1.0 WAR seems about right to me. I might be optimistic, but I'm not crazy.
My years of lurking on LL tell me that if Paxton and Walker are start the season well, there'll be a few "Four Aces, Bitches" headers in the comments. Take a deep breath and slow your heart rate. Three deuces with an Ace high is still a pretty solid hand.