Scouting Anthony Swarzak

The Cubs will face the Twins sometime after noon today. It's raining in Chicago, but that will clear up and rookie Anthony Swarzak will face the Cubs and Rich Harden (who is on a pitch count of about 85).

Swarzak has made four starts since being called up before Memorial Day. His first outing was his best.

date         vs    dec       IP      H     ER     BB      SO
2009-05-23  MIL      W      7.0      5      0      2      3
2009-05-28  BOS      L      6.0      5      3      4      3
2009-06-03  CLE      -      4.0      9      6      0      3
2009-06-08  oak      -      3.2      4      3      3      3

Swarzak throws a sinker along with a slurvey slider, four-seam fastball and change-up.

Type	#	vs LHH	vs RHH	MPH
Change	49	24	25	81.7
Sinker	224	100	124	91.6
Fastball	54	25	29	92.0
Slurve	38	11	27	76.6

Oddly, Swarzak looks to have thrown no four-seam fastballs in his latest, and shortest, outing. More on that after a segue into pitch classifcations. First, the spin movement and spin axis scatter graphs. Scroll on down if these make your eyes glaze over.

• Movement is in inches, catcher's perspective. Bubble size in the movement chart is based on speed.
• For the second chart for each start, spin axis is flipped to match the movement graphs, speed is on the y-axis and bubble size is based on spin rate.
• Spin axis has the arm angle subtracted out, spin movement does not.
• Confused? Leave questions in the comments.

The spin axis on the change, and therefore the movement, match the sinker, so I can see how that combination could be more effective/deceptive. And you could argue there were a few four-seamers in the mix on June 8. In any case, I'm not sure why he'd drop a pitch like that.

One way of looking at a pitch's effectiveness is to use linear weights, or run values. An average pitch would be rated a 0, and anything below 0 is good for the pitchers. Fangraphs shows you these numbers now, but I use my own data, pitch classifications and weight calculations, and I leave negative #'s negative, so you'll find differences if you compare the stats. Also, my weights are based on pitch count and outcome only, and are not adjusted for park factors.

Run value is cumulative and rv100 is a rate stat, averaged and adjusted to 100 pitches.

Pitch   Run Value   rv100
Change      1.947   3.973
Sinker     -1.583  -0.707
Fastball   -1.496  -2.771
Slurve      2.547   6.703

Often, a pitcher's best pitch isn't the one he'll throw the most. Maybe the infrequency is what makes it work. For a sinker baller, the four-seam is a "change" of sorts, and one that seems to have been used effectively, for three starts. If you're a Twins fan, you'll want him to bring it back today.

Roster Move
Bobby Scales is down to Iowa. Hart not up, as that would require another move. I must've imagined that (correction from earlier note here)