Do Hitter’s Get Their
Expected RBIs?
by Cyril Morong
For the most part, yes. If we assume hitter’s hit the same way with runners on base as they do all the time, they generally get about the number of RBIs we would expect based on how many base runners they are on when they bat and what bases they are on.
To calculate a hitter’s number of expected RBIs, I first computed how many runners were on first base when he batted, how many were on second base and how many were on third base. Then I computed how what his single, double, triple and homerun frequency. I then assumed he had the same frequency with runners on base as he did for all of his at bats. For example, if there were 2000 runners on first during the period (the data is explained below), and his homerun frequency is 3%, then we would expect him to get 60 RBIs for that case. Then we also assume that he hits homeruns 3% of the time when runners are on second base and third bases. The same is done for triples. Assume he hits triples with the same frequency as his overall triple rate and multiply that times how many base runners were on when he batted.
With singles and doubles, things are a little different. Of course runners on third and second will score on a double and a runner on third will score on a single. But I had to make assumptions about how often runners on first would score on a double and how often runners on second would score on a single. I assumed that 42.6% of runners scored from first on doubles and 63.4% scored from second. These were the major league averages for the years 1987-2000 that I got from John Jarvis’s website (http://knology.net/~johnfjarvis/stats.html).
Let’s look at an example. Jay Bell. Here is how many runners were on base when he batted, his hit frequencies, his expected RBIs in each case, and how many total RBIs we would have expected him to get (I had to adjust the numbers for at bats with runners on base I found at the CNN/SI site-this is explained in the section on the data below). This only includes RBIs from hits. RBIs from sacrifice flies and walks with the bases loaded are not included.
|
|
|
AB with |
AB with |
AB with |
AB with |
AB with |
|
|
|
|
None On |
Runners on |
Runners on 1st |
Runners on 2nd |
Runners on 3rd |
Situational |
|
|
|
4298 |
2921 |
1814 |
1396 |
708 |
Total |
|
1B% |
0.1773 |
0.00 |
N/A |
0.00 |
156.93 |
125.54 |
282.47 |
|
2B% |
0.0540 |
0.00 |
N/A |
41.75 |
75.42 |
38.25 |
155.41 |
|
3B% |
0.0093 |
0.00 |
N/A |
16.84 |
12.96 |
6.57 |
36.36 |
|
HR% |
0.0266 |
114.31 |
77.69 |
48.25 |
37.13 |
18.83 |
296.21 |
|
|
|
Expected RBI |
Expected RBI |
Expected RBI |
Expected RBI |
Expected RBI |
770.45 |
|
|
|
|
|
|
|
|
Grand Total |
If Jay Bell had the same hit frequencies with runners on base as he did overall, we would expect him to get 770.45 RBIs. The N/A in the fourth column for singles, doubles and triples is there because those expected RBIs are shown in the next three columns. For homeruns, there is a total in both the “None on” and “Runners on” columns since any homeruns in those cases give one RBI for the hitter over and above any runners on base.
Bell gets 114.31 expected RBIs from his at bats with none on from homeruns since .0266*4298 = 114.31. He gets 156.93 expected RBIs with runners on 2nd from singles since 1396*.1773*.634 = 156.93. He gets 41.75 expected RBIs with runners on 1st from doubles since 1814*.054*.426 = 41.75. I assumed that all runners on 3rd score on singles and all runners on 2nd score on doubles. He gets 16.84 expected RBIs with runners on from triples since 1814*.0093 = 16.84. I assumed that all runners scored on triples.
Adding up all of the individual cases gives 770.45 expected RBIs. During the years 1987-2001, Jay Bell actually got 776 RBIs, with sacrifice flies and bases loaded walks excluded. Below is a list of the 61 players who had 6000 or more plate appearances from the years 1987-2001 and who also had data listed at the CNN/SI site. The totals are per 600 at bats, or about a full season.
|
Name |
Actual |
Predicted |
Difference |
|
Tino
Martinez |
103.93 |
93.75 |
10.18 |
|
Jeff
Bagwell |
113.06 |
103.81 |
9.25 |
|
Frank
Thomas |
117.90 |
109.89 |
8.01 |
|
Wally
Joyner |
84.48 |
77.04 |
7.44 |
|
Robin
Ventura |
90.57 |
83.67 |
6.90 |
|
Dante
Bichette |
99.95 |
93.10 |
6.85 |
|
Harold
Baines |
94.28 |
87.51 |
6.77 |
|
Mark
Grace |
76.18 |
69.97 |
6.21 |
|
David
Justice |
103.19 |
96.99 |
6.21 |
|
B.J.
Surhoff |
75.98 |
70.02 |
5.96 |
|
Juan
Gonzalez |
123.21 |
117.78 |
5.43 |
|
Luis
Gonzalez |
87.50 |
82.46 |
5.05 |
|
John
Olerud |
87.83 |
83.08 |
4.76 |
|
Greg
Vaughn |
100.19 |
95.57 |
4.62 |
|
Paul
O'Neill |
94.80 |
90.19 |
4.60 |
|
Tony
Gwynn |
71.58 |
67.14 |
4.44 |
|
Travis
Fryman |
86.69 |
82.43 |
4.26 |
|
Gary
Sheffield |
98.15 |
94.06 |
4.08 |
|
Eric
Karros |
89.70 |
85.73 |
3.98 |
|
Jay
Buhner |
106.52 |
102.96 |
3.56 |
|
Bernie
Williams |
93.49 |
89.97 |
3.52 |
|
Barry
Bonds |
111.72 |
108.35 |
3.36 |
|
Ken
Griffey Jr. |
112.30 |
108.94 |
3.36 |
|
Mark
McLemore |
51.36 |
48.06 |
3.30 |
|
Kenny
Lofton |
55.16 |
51.87 |
3.29 |
|
Larry
Walker |
107.72 |
104.48 |
3.24 |
|
Jose
Canseco |
111.68 |
108.56 |
3.12 |
|
Andres
Galarraga |
102.89 |
99.77 |
3.12 |
|
Sammy
Sosa |
108.32 |
105.25 |
3.07 |
|
Ray
Lankford |
86.15 |
83.20 |
2.95 |
|
Delino
DeShields |
52.73 |
50.03 |
2.69 |
|
Will
Clark |
93.75 |
91.32 |
2.42 |
|
Todd
Zeile |
80.47 |
78.20 |
2.27 |
|
Mark
McGwire |
127.26 |
125.02 |
2.24 |
|
Matt
Williams |
99.05 |
96.96 |
2.10 |
|
Cal
Ripken |
79.41 |
77.61 |
1.81 |
|
Fred
McGriff |
100.76 |
99.09 |
1.67 |
|
Tim
Raines |
65.42 |
63.76 |
1.67 |
|
Edgar
Martinez |
97.80 |
96.44 |
1.36 |
|
Ken
Caminiti |
85.88 |
85.16 |
0.72 |
|
Jay Bell |
64.50 |
64.04 |
0.46 |
|
Gregg
Jefferies |
66.30 |
65.95 |
0.36 |
|
Brady
Anderson |
63.65 |
63.36 |
0.30 |
|
Rafael
Palmeiro |
96.95 |
96.67 |
0.29 |
|
Chuck
Knoblauch |
51.53 |
51.75 |
-0.22 |
|
Tony
Fernandez |
60.07 |
60.45 |
-0.39 |
|
Ruben
Sierra |
89.29 |
89.83 |
-0.55 |
|
Ron Gant |
86.37 |
87.04 |
-0.66 |
|
Roberto
Alomar |
71.11 |
71.86 |
-0.75 |
|
Marquis
Grissom |
60.58 |
61.59 |
-1.02 |
|
Bobby
Bonilla |
90.35 |
91.37 |
-1.02 |
|
Barry
Larkin |
68.58 |
70.52 |
-1.94 |
|
Devon
White |
64.56 |
66.50 |
-1.94 |
|
Steve
Finley |
66.49 |
68.46 |
-1.97 |
|
Dave
Martinez |
55.81 |
57.81 |
-2.00 |
|
Craig
Biggio |
59.81 |
61.86 |
-2.05 |
|
Omar
Vizquel |
47.01 |
49.76 |
-2.75 |
|
Rickey
Henderson |
55.40 |
58.45 |
-3.05 |
|
Benito
Santiago |
71.44 |
75.83 |
-4.39 |
|
Ellis
Burks |
93.29 |
99.86 |
-6.57 |
|
Wade
Boggs |
56.42 |
63.25 |
-6.83 |
Some observations. 47 of the 61 hitters (77%) were predicted to within 5 RBIs per 600 at bats. So this is reasonably accurate (the correlation between the actual RBIs and predicted RBIs is .987). But there are only 16 hitters who had fewer RBIs than expected. I expected about half the hitters to have more RBIs than expected and half to have less. A few RBIs come from groundouts and I don’t have data on those. But there are not many such cases.
Maybe my list of 61 players tends to be populated by very good hitters (who else would last so long?). They tend to bat in the middle of the order and the runners who are on base might be faster than average since they would be the 1 and 2 hitters. Also, these hitters may have more than average power. Maybe their singles and doubles go farther (and travel faster) than average, making it easier for runners to score.
Notice that the players who are above expectations also seem to be power hitters who hit in the middle of the order. The players who are negative tend to be players who batted at the top or bottom of the order. If they were at the top of the order, it might be partly because of their speed. So they may get more singles and doubles as a result of speed and the runners who are on already may not score. Also, if they have below average power, maybe their doubles and singles don’t go as far as they do for the power hitters, making it harder for runners to score.
But the bottom line is that the vast majority of hitters are predicted fairly well, and only one was off by more than 10 RBIs.
The assumed runner advancement is
for both leagues. I also tried using
different figures for hitters from each league. For the AL, 64.5% of runners scored from 2nd on singles and 39.5%
scored from 1st on doubles. For the NL, these were 62.3% and 45.7%,
respectively. For any players who did not get at least 80% of their at bats in
one league, I used a weighted average.
The results of that analysis is the left-hand column. Then I not only used the league runner
advance figures, but I also took into account the fact that, on average,
batting average is higher with runners on base (and HR% is lower). The differences are not great. Email me for details. These results are in
the right-hand column. In each case, I only give the difference between actual RBIs and expectations.
|
|
|
|
ADJ FOR
LEAGUE |
|
|
ADJ FOR
LEAGUE |
PER600 |
|
AND ROB |
PER600 |
|
Name |
AB |
|
Name |
AB |
|
Tino
Martinez |
10.29 |
|
Tino
Martinez |
9.76 |
|
Jeff
Bagwell |
9.10 |
|
Jeff
Bagwell |
8.55 |
|
Frank
Thomas |
8.15 |
|
Frank
Thomas |
7.63 |
|
Wally
Joyner |
7.45 |
|
Wally
Joyner |
6.56 |
|
Robin
Ventura |
6.93 |
|
Robin
Ventura |
6.34 |
|
Dante
Bichette |
6.81 |
|
Dante
Bichette |
6.05 |
|
Harold
Baines |
6.74 |
|
Harold
Baines |
6.02 |
|
David
Justice |
6.21 |
|
David
Justice |
5.74 |
|
Mark
Grace |
6.16 |
|
Mark
Grace |
5.21 |
|
B.J.
Surhoff |
6.00 |
|
Juan
Gonzalez |
5.16 |
|
Juan
Gonzalez |
5.58 |
|
B.J.
Surhoff |
5.13 |
|
Luis
Gonzalez |
4.90 |
|
Greg
Vaughn |
4.35 |
|
John
Olerud |
4.89 |
|
Luis
Gonzalez |
4.21 |
|
Greg
Vaughn |
4.66 |
|
John
Olerud |
4.13 |
|
Paul
O'Neill |
4.63 |
|
Paul
O'Neill |
3.83 |
|
Tony Gwynn |
4.44 |
|
Travis
Fryman |
3.60 |
|
Travis
Fryman |
4.34 |
|
Gary
Sheffield |
3.57 |
|
Gary
Sheffield |
4.03 |
|
Eric
Karros |
3.41 |
|
Eric
Karros |
3.89 |
|
Tony Gwynn |
3.38 |
|
Jay
Buhner |
3.64 |
|
Jay
Buhner |
3.32 |
|
Bernie
Williams |
3.61 |
|
Ken
Griffey Jr. |
3.09 |
|
Ken
Griffey Jr. |
3.43 |
|
Barry
Bonds |
2.90 |
|
Kenny
Lofton |
3.27 |
|
Jose
Canseco |
2.82 |
|
Mark
McLemore |
3.25 |
|
Bernie
Williams |
2.82 |
|
Barry
Bonds |
3.22 |
|
Sammy
Sosa |
2.76 |
|
Jose Canseco |
3.16 |
|
Kenny
Lofton |
2.56 |
|
Larry
Walker |
3.10 |
|
Larry
Walker |
2.47 |
|
Andres
Galarraga |
3.10 |
|
Andres
Galarraga |
2.43 |
|
Sammy
Sosa |
3.01 |
|
Mark
McLemore |
2.42 |
|
Ray
Lankford |
2.85 |
|
Mark
McGwire |
2.29 |
|
Delino
DeShields |
2.76 |
|
Ray
Lankford |
2.21 |
|
Will
Clark |
2.42 |
|
Delino DeShields |
1.99 |
|
Todd
Zeile |
2.23 |
|
Will
Clark |
1.59 |
|
Mark
McGwire |
2.21 |
|
Matt
Williams |
1.56 |
|
Matt
Williams |
2.05 |
|
Todd
Zeile |
1.49 |
|
Cal
Ripken |
1.84 |
|
Fred
McGriff |
1.19 |
|
Fred
McGriff |
1.67 |
|
Cal
Ripken |
1.19 |
|
Tim
Raines |
1.64 |
|
Tim
Raines |
0.82 |
|
Edgar
Martinez |
1.49 |
|
Edgar
Martinez |
0.68 |
|
Ken
Caminiti |
0.67 |
|
Ken
Caminiti |
-0.06 |
|
Jay Bell |
0.43 |
|
Rafael
Palmeiro |
-0.19 |
|
Rafael
Palmeiro |
0.36 |
|
Brady
Anderson |
-0.19 |
|
Gregg
Jefferies |
0.35 |
|
Jay Bell |
-0.27 |
|
Brady
Anderson |
0.34 |
|
Gregg
Jefferies |
-0.47 |
|
Chuck
Knoblauch |
-0.23 |
|
Chuck Knoblauch |
-0.97 |
|
Tony
Fernandez |
-0.41 |
|
Ron Gant |
-1.17 |
|
Ruben
Sierra |
-0.49 |
|
Ruben
Sierra |
-1.26 |
|
Ron Gant |
-0.67 |
|
Tony
Fernandez |
-1.42 |
|
Roberto
Alomar |
-0.76 |
|
Marquis
Grissom |
-1.67 |
|
Marquis
Grissom |
-0.97 |
|
Roberto
Alomar |
-1.68 |
|
Bobby
Bonilla |
-1.07 |
|
Bobby
Bonilla |
-1.84 |
|
Barry
Larkin |
-1.90 |
|
Devon
White |
-2.64 |
|
Devon
White |
-1.94 |
|
Steve
Finley |
-2.68 |
|
Dave
Martinez |
-1.99 |
|
Barry
Larkin |
-2.74 |
|
Steve
Finley |
-2.00 |
|
Craig
Biggio |
-2.79 |
|
Craig
Biggio |
-2.04 |
|
Dave
Martinez |
-2.85 |
|
Omar
Vizquel |
-2.84 |
|
Rickey
Henderson |
-3.67 |
|
Rickey
Henderson |
-3.07 |
|
Omar
Vizquel |
-3.74 |
|
Benito
Santiago |
-4.38 |
|
Benito
Santiago |
-5.13 |
|
Ellis
Burks |
-6.56 |
|
Ellis
Burks |
-7.30 |
|
Wade
Boggs |
-6.84 |
|
Wade
Boggs |
-7.85 |
The results are similar to the first case, although some players have noticeably bigger (or smaller) differences between actual and expected RBIs.
I also looked at
this issue with walks included. That
is, for a player’s hit frequency, I used at bats + walks + HBP as the
denominator. Of course, it also meant
that there were more runners to drive in.
The lists below are those three cases.
Again, the results are similar what we have already seen. I just show the difference between actual RBIs and expectations per 660 plate
appearances. RBIs from bases loaded
walks are included but not RBIs from sacrifice flies. The column on the left
makes no adjustment for what league a hitter was in. The one in the center does.
The one on the left adjusts for league and the normally higher hit
frequencies with runners on base (and lower HR%s with runners on).
|
|
|
|
ADJUSTED |
|
|
ADJUSTED
FOR |
ROB |
|
NO ADJ |
PER660 |
|
FOR
LEAGUE |
PER660 |
|
LEAGUE
AND |
PER660 |
|
Name |
PA |
|
Name |
PA |
|
Name |
PA |
|
Tino
Martinez |
9.11 |
|
Tino
Martinez |
9.24 |
|
Tino
Martinez |
8.80 |
|
Dante
Bichette |
7.11 |
|
Dante
Bichette |
7.06 |
|
Dante
Bichette |
6.84 |
|
Jeff
Bagwell |
6.78 |
|
Harold
Baines |
6.77 |
|
Harold
Baines |
6.28 |
|
Harold
Baines |
6.77 |
|
Jeff
Bagwell |
6.64 |
|
Jeff
Bagwell |
6.22 |
|
Mark
Grace |
6.16 |
|
Mark
Grace |
6.11 |
|
Mark
Grace |
5.59 |
|
B.J.
Surhoff |
5.87 |
|
B.J.
Surhoff |
5.91 |
|
B.J.
Surhoff |
5.41 |
|
Robin
Ventura |
5.62 |
|
Robin
Ventura |
5.67 |
|
Robin Ventura |
5.19 |
|
Wally
Joyner |
5.61 |
|
Wally
Joyner |
5.62 |
|
Wally
Joyner |
5.08 |
|
Frank
Thomas |
5.41 |
|
Frank
Thomas |
5.55 |
|
Frank
Thomas |
4.72 |
|
Juan
Gonzalez |
4.20 |
|
Juan
Gonzalez |
4.37 |
|
Juan
Gonzalez |
4.06 |
|
David
Justice |
3.93 |
|
Paul
O'Neill |
3.95 |
|
David
Justice |
3.69 |
|
Paul
O'Neill |
3.92 |
|
David
Justice |
3.93 |
|
Jose
Canseco |
3.63 |
|
Luis
Gonzalez |
3.64 |
|
Travis
Fryman |
3.68 |
|
Greg
Vaughn |
3.55 |
|
Travis
Fryman |
3.58 |
|
Jose
Canseco |
3.62 |
|
Eric
Karros |
3.44 |
|
Jose
Canseco |
3.57 |
|
Greg
Vaughn |
3.54 |
|
Paul
O'Neill |
3.43 |
|
Greg
Vaughn |
3.50 |
|
Luis Gonzalez |
3.51 |
|
Travis
Fryman |
3.36 |
|
Eric
Karros |
3.44 |
|
Eric
Karros |
3.37 |
|
Luis
Gonzalez |
3.16 |
|
Kenny
Lofton |
3.24 |
|
Kenny
Lofton |
3.24 |
|
Kenny
Lofton |
2.94 |
|
Tony Gwynn |
3.22 |
|
Tony Gwynn |
3.22 |
|
Tony Gwynn |
2.47 |
|
Ken
Griffey Jr. |
2.75 |
|
Ken
Griffey Jr. |
2.85 |
|
Mark
McLemore |
2.34 |
|
Mark
McLemore |
2.72 |
|
Bernie
Williams |
2.81 |
|
Bernie
Williams |
2.28 |
|
Bernie
Williams |
2.71 |
|
Mark
McLemore |
2.69 |
|
Jay
Buhner |
2.24 |
|
Delino
DeShields |
2.47 |
|
Delino
DeShields |
2.54 |
|
Delino
DeShields |
2.19 |
|
Andres
Galarraga |
2.17 |
|
John
Olerud |
2.32 |
|
Ken
Griffey Jr. |
2.03 |
|
John
Olerud |
2.17 |
|
Jay
Buhner |
2.22 |
|
Sammy
Sosa |
1.87 |
|
Gary
Sheffield |
2.14 |
|
Andres
Galarraga |
2.16 |
|
Andres
Galarraga |
1.87 |
|
Jay
Buhner |
2.13 |
|
Gary
Sheffield |
2.09 |
|
Gary
Sheffield |
1.85 |
|
Sammy
Sosa |
2.10 |
|
Sammy
Sosa |
2.05 |
|
John
Olerud |
1.47 |
|
Matt
Williams |
1.10 |
|
Matt
Williams |
1.05 |
|
Matt
Williams |
0.91 |
|
Will
Clark |
0.95 |
|
Will
Clark |
0.94 |
|
Mark
McGwire |
0.46 |
|
Larry
Walker |
0.64 |
|
Cal
Ripken |
0.68 |
|
Will
Clark |
0.35 |
|
Mark
McGwire |
0.63 |
|
Mark
McGwire |
0.61 |
|
Cal
Ripken |
0.29 |
|
Cal
Ripken |
0.63 |
|
Larry
Walker |
0.52 |
|
Ray
Lankford |
0.28 |
|
Ray
Lankford |
0.60 |
|
Ray
Lankford |
0.51 |
|
Todd
Zeile |
0.24 |
|
Todd
Zeile |
0.51 |
|
Todd
Zeile |
0.49 |
|
Larry
Walker |
0.18 |
|
Fred
McGriff |
0.44 |
|
Fred
McGriff |
0.44 |
|
Fred
McGriff |
0.06 |
|
Barry
Bonds |
0.08 |
|
Barry
Bonds |
-0.07 |
|
Jay Bell |
-0.45 |
|
Jay Bell |
-0.21 |
|
Jay Bell |
-0.22 |
|
Brady
Anderson |
-0.97 |
|
Edgar
Martinez |
-0.59 |
|
Edgar
Martinez |
-0.44 |
|
Chuck
Knoblauch |
-0.99 |
|
Chuck
Knoblauch |
-0.66 |
|
Chuck
Knoblauch |
-0.65 |
|
Edgar
Martinez |
-1.13 |
|
Brady
Anderson |
-0.73 |
|
Brady
Anderson |
-0.67 |
|
Tim
Raines |
-1.17 |
|
Tim
Raines |
-0.77 |
|
Tim
Raines |
-0.79 |
|
Barry
Bonds |
-1.32 |
|
Tony
Fernandez |
-0.96 |
|
Tony
Fernandez |
-0.98 |
|
Tony
Fernandez |
-1.44 |
|
Gregg
Jefferies |
-1.24 |
|
Gregg
Jefferies |
-1.24 |
|
Ron Gant |
-1.45 |
|
Ruben
Sierra |
-1.33 |
|
Ruben
Sierra |
-1.25 |
|
Gregg
Jefferies |
-1.68 |
|
Ron Gant |
-1.45 |
|
Ron Gant |
-1.46 |
|
Ruben
Sierra |
-1.75 |
|
Ken
Caminiti |
-1.48 |
|
Ken
Caminiti |
-1.52 |
|
Ken
Caminiti |
-1.96 |
|
Roberto
Alomar |
-1.60 |
|
Roberto
Alomar |
-1.61 |
|
Roberto
Alomar |
-1.99 |
|
Rafael
Palmeiro |
-1.95 |
|
Rafael
Palmeiro |
-1.86 |
|
Rafael
Palmeiro |
-2.28 |
|
Marquis
Grissom |
-2.09 |
|
Marquis
Grissom |
-2.04 |
|
Marquis Grissom |
-2.33 |
|
Steve
Finley |
-2.26 |
|
Steve
Finley |
-2.28 |
|
Steve
Finley |
-2.51 |
|
Bobby
Bonilla |
-2.69 |
|
Bobby
Bonilla |
-2.74 |
|
Devon
White |
-3.02 |
|
Devon
White |
-2.77 |
|
Craig
Biggio |
-2.76 |
|
Craig
Biggio |
-3.11 |
|
Craig
Biggio |
-2.77 |
|
Devon
White |
-2.76 |
|
Bobby
Bonilla |
-3.19 |
|
Omar
Vizquel |
-2.89 |
|
Omar
Vizquel |
-2.96 |
|
Omar
Vizquel |
-3.29 |
|
Barry
Larkin |
-3.62 |
|
Barry
Larkin |
-3.58 |
|
Barry
Larkin |
-3.95 |
|
Dave
Martinez |
-3.72 |
|
Dave
Martinez |
-3.71 |
|
Dave
Martinez |
-4.06 |
|
Rickey
Henderson |
-5.14 |
|
Rickey
Henderson |
-5.16 |
|
Rickey
Henderson |
-5.32 |
|
Benito
Santiago |
-5.34 |
|
Benito
Santiago |
-5.32 |
|
Benito
Santiago |
-5.60 |
|
Ellis
Burks |
-7.10 |
|
Ellis
Burks |
-7.09 |
|
Ellis
Burks |
-7.17 |
|
Wade
Boggs |
-8.64 |
|
Wade
Boggs |
-8.63 |
|
Wade
Boggs |
-9.30 |
Again, the results are similar to the analysis based on at bats only.
I came across a discrepancy in the data I used. I used data from the CNN/SI site for each player and I calculated each player's RBI opportunities. For example, I added up the at-bats that CNN/SI reported for Rafael Palmeiro for each situation where runners might be on base
Runner on 1B-1262
Runner on 2B-714
Runner on 3B-236
Runners on 1B, 2B-614
Runners on 1B, 3B-249
Runners on 2B, 3B-142
Bases Loaded-163
This adds up to 3380. But the discrepancy comes in where, in a separate line, they report that he had 3852 at-bats with runners on base, not 3380. With no runners on, they give him 4521. Adding this to 3852, you get 8373, the same total that he has in the Lee Sinins sabermetric encyclopedia (for 1987-2001). So the 3852, not the 3380, must be right.
In my study I looked at opportunities per at-bat. So I had to calculate opportunities for each hitter. For Palmeiro it was
1262*2=2524
714*2=1428
236*2=472
614*3=1842
249*3=747
142*3=426
163*4=652
If you add that up, you get 8091. The reason you multiply 1262 by 2 is that an at-bat with a man on first is two opportunities, the man on first and the batter. Adding the 8091 to the at-bats with none on (which is one opportunity each time), 4521, you get 12612. That is, Palmeiro had 12612 opportunities. To get this per at-bat, you divide 12612 by his total at-bats, 8373, and get 1.51.
Now this is not right, because I did not have the right numbers for each of those base situations. I don't know why CNN/SI had the discrepancy. I discovered it on August 1, 2003.
Then I looked at how many runners on base at-bats were missing for Palmeiro. That would be 3852 - 3380 or 472. The 3852 is 13.96% higher than the 3380. I assumed that Palmeiro got those other 472 at bats and that the seven base situations came up with the same frequency as they did for the at-bats listed. So I raised the at-bats with a runner on first 13.96%, the at-bats with a runner second 13.96%, and so on. So Palmeiro gets more opportunities and then opportunities per at-bat goes up to 1.64. I did this for all the hitters and re-ran the first regression from the paper. The results were actually more accurate, with the coefficients on ISO and AVG changing a little but the coefficient on OPP (RBI opportunities) went up to .187 from .125. That is quite a jump and it means that opportunities might be alot more important than I thought. In fact, I had done a study on the 1995 season a couple of years ago, and the coefficient on OPP was .174. The standard error per 600 at bats fell from 5.03 to 3.39.
If you went to the CNN/SI site to look for these discrepancies, you would not be able to find them. They no longer list all of the base out situations. They leave one out, the one with runners on first. So you can’t check the total at bats from the seven on-base situations with the total given in the separate “runners on base” line. Since they had a discrepancy before, it might still exist and you could not detect it.
I think the corrections I have made are very reasonable. They result in average number of opportunities per at bat of 1.62. Before the corrections, it was just 1.52. The 1.62 is more in line with what I got in a study of the 1995 season (I used data from the STATS, INC. Scoreboard book for that study) and also with the frequency of the different base-out situations. There was quite a range of discrepancies. Two hitters were missing more than 20% of their at bats with runners on base while two were missing less than 1%. That is, the discrepancies varied quite a bit across players.