Tuesday, March 26, 2019

How Many Runs Will The Tigers Allow in 2019?

It was a lot more fun making projections for the Tigers staff when they had Justin Verlander (Photo credit:GiveMeSport)

Now that I have projected the Tigers runs scored total for 2019, the next step is to estimate how many runs they will give up.  Compared to run production, run prevention is more difficult to predict because pitcher's arms are so fragile and their performance so volatile.  I undershot the Tigers eventual run total in each of the last four seasons:

2014 65
2015 129
2016 30
2017 194
2018 6

After being off by 194 runs in 2017, I was about to give up on this process, but last year was a lot better.  Before the 2018 season got under way, I wrote that the Tigers would allow 790 runs.  They went on to surrender 796 runs.  So, I was off by six runs giving me hope that my formulas have some utility.  

General Manager Al Avila made a couple of moves during the off-season to add pitching depth.  Most notably, he added two starters - left hander Matt Moore and right hander Tyson Ross.  Neither is likely to be good or even average, but they will give the Tigers innings which will keep them from rushing young pitchers into major league action.  It was also hoped that righty  Michael Fulmer would come back healthy, but he will miss the season due to Tommy John surgery.  

Their rotation to start the season will consist of  Moore, Ross, Matt Boyd, Jordan Zimmermann and rookie Spencer Turnbull which sounds like a Randy Smith rotation from the mid 90s.  It is hard to even predict how long any of the starters will remain in the rotation.  If they fail, the first two replacements would likely be Daniel Norris and Blaine Hardy.    
  
For the projection, I first estimated innings pitched in 2019 for the seven starters listed above and key bullpen pieces at the beginning of the season (Table 1).  In order to forecast runs allowed, I used three-year averages on three measures from 2016-2018 all adjusted for projected innings this year:
  • Runs Allowed.
  • Base Runs - estimate of what runs allowed should have been based on base runners, total bases and home runs.
For example, Boyd allowed an average of 105 runs per 180 innings (his projected 2019 total) from 2016-2018.  He also allowed 105 Base Runs and 91 FIP Runs.  The average of the three numbers above (105, 105, 91) was 100.  That comes out to an Earned Run Average of about 4.66 which seems about right for him.  

I projected the rest of the pitchers moving them up or down from their three-year averages if I think they are going to get better or worse this year.  In particular, I'm guessing that reliever Joe Jimenez  will do better than his three-year average.  I made a big adjustment for Turnbull because it doesn't make much sense to base a projection on just 16 past innings.

Summing it all up, I am projecting 823 runs allowed which is worse than last year when they had Fulmer plus a surprisingly solid season from Mike Fiers.  That combined with 690 runs scored yields a differential of 133 runs or thirteen wins below .500.  Thus, my prediction for the season is a 68-94 record.  This would be better than their 98 losses in 2017 and 2018, but not because of their pitching.         

Table 1: Projected Runs Allowed By Tigers Pitchers in 2019
Pitcher
Proj IP
RA
BSR
FIP Runs
Comb*
Proj Runs
Proj ERA
Matt Boyd
180
105
105
91
100
100
4.66
Jordan Zimmermann
160
111
109
90
103
103
5.41
Matt Moore
150
92
87
78
86
86
4.80
Tyson Ross
150
94
79
80
84
84
4.72
Spencer Turnbull
140
96
59
44
66
80
4.78
Daniel Norris
100
57
61
47
55
55
4.59
Blaine Hardy
85
42
44
40
42
48
4.73
Joe Jimenez
65
50
35
26
37
30
3.86
Shane Greene
65
34
29
28
30
30
3.90
Other
345
.
.
.
207
207
5.02
Totals
1,440



811
823
4.78



















*Average adjusted for projected innings in 2019.
 Data Source: Baseball-Reference.com

Sunday, March 24, 2019

How Many Runs Will The Tigers Score In 2019?

The health of first baseman Miguel Cabrera will be a big determinant in how many runs the Tigers score in 2019 (Photo source: Crain's Detroit Business).

It is time for my annual runs scored prediction for the Tigers.  Table 1 below shows that I had been pretty good (lucky?) at projecting the Tigers team run totals for a few years, but not so good last year.  

Table 1: Tigers Projected and Actual Runs Scored, 2013-2018
Year
Proj. Runs
Runs
Diff
Pct Diff
2013
800
796
+4
0.0%
2014
760
757
+3
0.0%
2015
770
689
+81
10.5%
2016
755
750
+5
0.7%
2017
750
735
+15
2.0%
2018
685
630
+55
8.7%

In 2013, I projected that they would score 800 runs and they actually scored 796, so I was off by just four runs. Moreover, I missed by just three and five runs respectively in 2014 and 2016. Thus, my forecasts came within 1% of the actual runs scored those three years.

It gets more difficult when your legendary slugging first baseman has his season derailed by injuries and two of your best hitters are shipped elsewhere during an in-season fire sale.  Given that, it is surprising, that I was off by only 15 (a two percent difference) in 2017. 

My formula did not work so well in 2015 when I predicted they would score 770 and they instead scored 689, a difference of 81 runs.  Much of the discrepancy was accounted for by injuries to first baseman Miguel Cabrera and designated hitter Victor Martinez and the mid-season fire sale which sent outfielder Yoenis Cespedes to the Mets.  

In 2018, I predicted that the Tigers would score 685 runs, but they only scored 630, a difference of 55 runs.  What went wrong was that I was too optimistic regarding Miguel Cabrera.  I had him pegged for 600 plate appearances and a big comeback season.  Instead, he missed most of the season with a ruptured biceps which limited him to just 157 plate appearances.    

The Weighted Runs Created (wRC) statistic at FanGraphs is useful for this kind of exercise because a team's Runs Created total usually falls fairly close to its run scored total.  Most teams have Runs Created within 5% of their runs scored.  The Tigers combined for 609 Runs Created in 2018 which was 21 (or 3%) fewer than their actual runs scored.  

One reason why the Tigers scored more runs than they created last year is that Runs Created does not account for runs gained from base running.  The Tigers gained 6 runs due to base running (According to FanGraphs baserunning runs statistic).  It also may have helped that they hit for a higher OPS with runners on base than with the bases empty (.731 versus .643).

Keeping the above caveats in mind, the Runs Created measure is generally helpful in projecting future offensive production.  Table 2 below lists the Tigers most likely regulars in 2019 and their estimated plate appearances (PA).  In the next column is the three-year average of Runs Created adjusted for expected PA.  For example, Cabrera had 210 Runs Created in 1,365 plate appearances over 2016-2018 which comes out to .154 Runs Created Per PA.  Multiplying .154 times 500 PA (his projected PA for 2019) yields an adjusted three-year average of  77 Runs Created.

The final column of the table is my forecast for Runs Created in 2019.  In all cases, it is fairly close to the three-year average, but I make adjustments if I think a player will improve or regress this year. I don't have a formula for doing that.  It is just a judgement call based on what I know about things that an average of past seasons might not take into account such as advancing age or a change in a player's health.  

In Cabrera's case, I am projecting that he will be right on his three-year average.  I would normally knock a 36-year-old player down a few notches, but his poor health brought down his performance the last two years.  Perhaps, I am being too optimistic again assuming better health this year, but so far he seems to be in good shape.  On the other hand, I expect that the keystone combination of Josh Harrison and Jordy Mercer will both regress a bit with age. 

Aggregating all the projected Runs Created yields 690 for the team which is very close to what I predicted last year.  That would be 60 runs more than last year, but I think it can happen if Cabrera stays healthy and rookie outfielder Christin Stewart holds his own for a full season

Table 2: Tigers Projected Runs in 2019
Player
PA
Runs Created
3-Yr Avg*
2019
Proj
Greiner
450
39
42
Cabrera
500
77
77
Harrison
550
61
57
Mercer
550
59
55
Candelario
650
75
75
Castellanos
650
95
95
Jones
450
33
36
Stewart
450
63
60
Goodrum
550
65
65
Hicks
300
36
36
Mahtook
300
35
35
Others
650
        --
52
Base Running/DP
         --
5
5
Totals
6,050
693
690
*Adjusted for expected plate appearances in 2019

Data source: FanGraphs.com

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