Tuesday, August 5, 2008

Profile: Felix Hernandez

A 22 year old starter with a career xERA of 3.44 over 601.2 IP is not exactly a common occurrence. Felix Hernandez has produced those numbers since his debut at age 19 in 2005 by striking out batters (8.45 K/9), and inducing groundballs (58.5 GB%). Hernanez ranks fourth in PWAR over the last three years, and still has plenty of time to improve.

How does Hernandez do what he does? Let's take a look at some pitchfx data from his 2008 season.

Stuff

Velocity

Pitch Hernandez Average
Fastball 96.89 91
Curveball 83.15 (13) 77 (14)
Slider 89.53 (7) 84 (7)
Changeup 86.86 (10) 82 (9)

The numbers in parenthesis are the difference between that pitch and the fastball. Hernandez clearly has elite velocity, and keeps that velocity up with all 4 of his pitches.

Movement



Felix
League Average

Pitch Horiz Move
Vert Move
Move Angle
Fastball -6.07 -6.2 6.68 8.9 -112.7 -60.8
Curveball 5.7 5.2 -5.47 -3.3 -81.8 -42.2
Slider 1.8 0.7 -0.38 3.7 -12.3 -88.7
Changeup -6.05 -7.4 3.41 6 -36.2 -60.3


The graph is from the point of view of the hitter, so negative horizontal break is toward a right handed hitter. The vertical movement is compared to a theoretical pitch without spin, so positive numbers aren't pitches that literally rise, just pitches that don't drop as much.
First of all, Hernandez get significantly above average movement both horizontally and vertically, but especially vertically. Notice the 4+ inches of vertical drop between Hernandez and the average slider. That's a huge difference, making his slider almost as close to a curveball as it is to a slider in terms of movement. Of course, if you go back to the velocity table, his slider is closer to being a fastball in terms of velocity. This is quite a pitch. Compared to the average fastball, Felix's fastball breaks in to righties significantly more than his other pitches. The movement difference between his fastball and changeup is nearly entirely vertical, which is quite different than the league average. In fact, the average fastball and changeup have nearly the same angle of break. Felix's curveball is about what would be expected looking at his other pitches.

Results

FB- Fastball; SL- Slider; CB: Curveball; CU: Changeup

Pitch Ball%
Called K%
Foul%
Swinging K%
InPlay%
FB 0.36 0.34 0.19 0.19 0.19 0.20 0.06 0.05 0.19 0.23
SL 0.36 0.37 0.14 0.19 0.17 0.12 0.13 0.21 0.20 0.11
CB 0.40 0.36 0.19 0.22 0.13 0.16 0.11 0.13 0.16 0.13
CU 0.40 0.36 0.11 0.18 0.14 0.15 0.13 0.12 0.21 0.19
All 0.37 0.35 0.17 0.19 0.17 0.17 0.09 0.10 0.19 0.19

The only pitch that is called a ball more than average, his slider, is either a called strike or swinging strike an extra 13% of the time. Hitters really can't put this pitch into play. Beyond that, Hernandez is simply a bit better, but better across the board for significant value.

Now lets look at what happens when the ball is hit into play (AVG and SLG include HR)

Pitch AVG
BABIP
SLG
HR%
FB 0.330 0.381 0.304 0.372 0.521 0.504 0.037 0.015
CB 0.310 0.486 0.290 0.441 0.471 0.811 0.029 0.081
SL 0.310 0.314 0.286 0.255 0.481 0.667 0.033 0.078
CU 0.319 0.162 0.295 0.139 0.502 0.270 0.035 0.027
All 0.323 0.362 0.298 0.342 0.506 0.532 0.035 0.030

Besides his dominating changeup, Hernandez's pitches don't fare too well when put into play. This may be just a product of the pitches that were recorded by pitchfx; his actuall BABIP is .311, compared to the .342 listed in "All" on this chart. He has, however, prevented giving up homers with his fastball, which must be due to the above average sink he puts on it.

PitchType nipRuns nipR100 bipRuns bipR100 TOTAL runs100
FB -12.35 -1.35 17.46 6.47 3.76 0.32
CB -5.14 -2.04 7.53 20.35 0.35 0.12
SL -9.10 -2.23 4.36 8.55 -6.97 -1.52
CU -2.60 -1.62 -3.66 -9.89 -7.88 -3.98
All -29.18 -1.68 25.69 6.50 -10.73 -0.50

This table requires some explanation. First of all, "nip" is not in play, and "bip" is ball in play (include HR). Second of all, all the "Run" values are based on linear weights. The linear weights for balls and strikes come from here. I used a constant based on the average number of times reaching each count. R100 is runs per 100 pitches, which also comes from here

Now onto the actual results. These numbers give a total picture of Hernandez's results using each pitch. Hernandez dominates when he keeps the ball out of play. All of his pitchers are over -1 run per 100 pitches when not put in play, quite an impressive accomplishment. The bipR100 vary greatly, and some of that is probably due to the luck involved on balls in play. His slider is probably his best pitch, but the value of his changeup is clearly not all luck. That extra sink on his changeup seems to be helping Felix avoid hits, especially of the extra base variety.

Summary

Not surprisingly, Hernandez has 4 above average pitches in terms of movement, velocity, and results. His slider is unique, and has results to match its speed and movement. His impressive fastball is a great pitch, but its his offspeed stuff that really sets him apart. Amazingly just 22 years old, Hernandez is probably the best pitcher in the game if you consider age, experience, talent, and results.

All pitchfx stats come from Josh Kalk's
http://www.baseball.bornbybits.com

Sunday, August 3, 2008

The Best Pitchers in the Major Leagues

After compiling a bunch of xERA numbers, I decided to take a look at the top pitchers in baseball right now. I ranked starters by Peripheral Wins Above Replacement (PWAR), which came from xRA and xIP numbers. I took each players numbers over the last 3 calendar years (thanks fangraphs), and simply found wins above replacement per year over that three year span. This isn't a list of who has the most value over any amount of time or who has the most trade value, it's just who have been the best pitchers over the last 1095 days.

1. Johan Santana, 4.14 PWAR
8.96 K/9, 2.04 BB/9, 39.7 GB%
661 xIP, 3.39 xERA

There's a reason that this guy caused so much attention when he was on the trade market last winter. The GB% is below average, but those walks and strikeouts are fantastic. Santana is 29 and while he probably won't be posting ERA's below 3 anymore, he has a few more years to be included in the conversation on who the best pitcher in the majors is. While his K and BB numbers this year aren't quite what they used to be, his GB% is at a career high 42.7%.

2. Brandon Webb, 4.06 PWAR
7.26 K/9, 2.26 BB/9, 64.3 GB%
677 xIP, 3.46 xERA

When you're the best groundball pitcher in the majors and have 3.21 K/BB, you deserve to be mentioned among the elite. Webb will earn $5.5M this year, $6.5M next year, and has a club option for $8.5M in '10, making him on of the best values for a pitcher in his prime. Webb's PWAR suggests value of over $16M, and if he continues to induce those kind of GB's with those K and BB, he may see that kind of money if he hits the market in '11 at the age of 32.

3. CC Sabathia, 3.91 PWAR
8.22 K/9, 1.96 BB/9, 46.1 GB%
665 xIP, 3.49 xERA

Last year's Cy Young winner will make quite a lot of money this winter, and whatever team is able to sign him will certainly get some value out of that contract. As great as CC was last year, he's been just as good this year, with the highest K/9 of his career and the second best GB%. Sabathia has been fantastic since '06, with both an ERA and FIP under 3.30 in each of those years. Analysts often mention how Sabathia has "learned to pitch" in the past few years, a thought which is backed up by the numbers. Sabathia lowered his BB/9 each year from '01-'07, from a replacement-level 4.74 in his rookie year to an elite 1.38. Sabathia has also gone from throwing 66.3% fastballs in '05 to 55.2% fastballs this year, while raising his slider % from 15.3 to 25.2% in that time. This newfound ability to mix things up is the root of Sabathia's improved K and GB rates.

4. Felix Hernandez, 3.66 PWAR
8.15 K/9, 2.81 BB/9, 58.5 GB%
600.5 xIP, 3.44 xERA

The fact that a 22-year-old has posted these numbers over the last 3 years is pretty nuts. I'd like to do a complete profile of this pitcher who posted a 2.85 FIP over 85.1 IP at the age of 19, but for now I'll stick to the basics. Hernandez could be the best pitcher in the majors very soon, and he's still a few years away from his prime. Felix has been homer-lucky this year (7.8 HR/FB), and the grounders aren't quite what they used to be (51.1% in '08), but the strikeouts are encouraging (8.40 K/9). Hernandez is the probably the hardest throwing starter in the majors, as his 95.3 mph average fastball over the last three years has been the best among MLB starters. Felix's career is just beginning, and it should be an entertaining one to watch.

5. Jake Peavy, 3.58 PWAR
9.39 K/9, 2.71 BB/9, 41.4 GB%
595 xIP, 3.45 xERA

Last year Peavy rode a 2.54 ERA to a 19-6 record and the NL Cy Young title. His FIP wasn't quite as low, although it did as well lead the majors at an impressive 2.84. However, FIP is not immune to ballpark issues, which were definitely prevalent in Peavy's 5.8% HR/FB rate. This year, Peavy has kept his ERA below his peripherals in a different way, by stranding 84.5% of runners. While his BB/9 has improved, he isn't striking out quite as many batters as in the past couple years and his GB%, which was a career high 44.0% last year, is back down to 41.0%. Looking at his pitch selection from the past three years, the difference that stands out most is his use his offspeed pitches, throwing 27.6% offspeed compared to 33.1 offspeed in '07. In '06, when he had a 38 GB% and a 3.51 FIP, he threw just 25.5% offspeed. Peavy could get that GB% back to his '07 level if he started to throw more offspeed pitches. It may cost him a few walks, but those GB are the difference between the 3.16 xERA he sported in '07 and the 3.85 xERA he has this year.

Here's the rest of the top 10.

6. Dan Haren, 3.54 PWAR
7. Derek Lowe, 3.24 PWAR
8. Javier Vazquez, 3.14 PWAR
9. Josh Beckett, 2.97 PWAR
10. Scott Kazmir, 2.81 PWAR

Just for fun, I'll list my opinion on the top five for a few periods of time.

Best Pitcher for 2009
1. Brandon Webb
2. CC Sabathia
3. Johan Santana
4. Jake Peavy
5. Felix Hernandez

Best Pitcher for 2009-2011
1. CC Sabathia
2. Brandon Webb
3. Jake Peavy
4. Felix Hernandez
5. Johan Santana

Best Pitcher for 2009-2014
1. CC Sabathia
2. Felix Hernandez
3. Brandon Webb
4. Jake Peavy
5. Scott Kazmir



Stats came from the irreplaceable fangraphs.com

Friday, August 1, 2008

DIPS don't lie

Defensive Independent Pitching Statistics are a very important part of baseball analysis. They take away the issues that are brought about by Wins, ERA, and other commonly used pitching stats. Here is my attempt to use a few stats to break defense away from pitching to reach xERA, the expected ERA based on things the pitcher can control.

The stats I used were IP, H, BB, K, LD%, GB%, and FB%. IP and H were basically used just to find a rough representation of BF. I did this because I was using Fangraphs' export feature to calculate for a long list of data. Here are the steps.

Outs = IP*3

Balls Hit (BH) = Outs - K + H
Basically Ball in Play plus HR. HR are usually seperated but will be dealt with later.

xHits = ((.734*LD%)+(.245*GB%)+(.217*FB%)*BH
The coefficients come from the MLB batting averages on each type of hit type.

xTotalBases = ((1.016*LD%) + (.267*GB%) + (.574*FB%))*BH
Same as xHits, except with SLG instead of BA. This is also where HR are dealt with, as the Slugging Percentages include HR, and HR are mostly a product of GB/FB ratio.

xBA = xH/(Outs + H)
xOBP = (xH+BB)/(Outs + H + BB)
xSLG = xTB/(Outs + H)

Now that we have defensive independent BA/OBP/SLG, we can find out xRunsAllowed. I decided to use GPA because of its simplicity and ability to be converted into Runs.

xGPA = (1.8*xOBP + xSLG)/4
xRA = (Outs+H+BB)*1.356*(xGPA^1.77)

Now that we have xRA, we just have to find out xIP, which is basically xOuts based on xOBP.

xIP = ((Outs+H+BB)*(1-xOBP))/3

Simple. Now xRA/9

xRA/9 = xRA*9/xIP

Since this includes unearned runs, it won't be on the same scale as ERA. Since the difference between ERA and RA is about .360

xERA = xRA/9 - .360

And that's about it.

Here are some results:

All qualified 2008 Pitchers

All qualifed 2007 Pitchers