Angus on Baserunning

Jeff Angus, author of the Management by Baseball weblog has written a nice piece on baserunning over at Baseball Analysts where he mentions my work on baserunning. Thanks Jeff.

In that article he notes that he's using data that goes through August. I now have run my framework for 2005, complete results from which will be published in the 2006 Hardball Times Annual (order yours today), and here are the top 10 baserunners listed by opportunities. Keep in mind that these opportunities consist of those where the runner was on first with second empty and the batter singles, the runner is no first with second empty and the batter doubles, and when the runner is on second with third empty and the batter singles.

These numbers are also park and situation adjusted and the columns mean:

• Bases - the number of bases gained in these situations. This number differs from what Angus showed since he calculates a "safe %" indicating how often the runner took the extra base


• OA - the number of times the runner was out advancing the extra base


• IB – the difference between the actual and expected bases gained. Negative values indicate that the base runner did not advance as many bases as an average player would have given the same opportunities


• Base Runner Runs or BRR – the total number of runs a runner can be attributed given his base running performance in the opportunities he had (given our three scenarios above)


• Incremental Runs or IR – the difference between the BRR and the expected number of runs. Negative values indicate that the runner performed poorly in his opportunities by not taking as many bases and therefore contributing fewer runs than he should have


• Incremental Run Percentage (IRP) – a rate statistic calculated as the ratio of IR to BRR. IRP is akin to OPS+ in that it shows at what rate players contribute runs with their base running. Values over 1 indicate players who contributed above what would have been expected while values under 1 indicate a poor performance. IRP is needed for player comparisons since IR, like RBIs, is weighted by opportunity.

Drum roll please....

Team    Name             Opp Bases OA    IB   BRR    IR  IRP
NYA     Derek Jeter       69   105  3   4.4  7.99  0.99  114
BOS     Johnny Damon      66   100  2  -1.4 10.38 -0.24   98
BAL     Miguel Tejada     65    99  1   3.1 10.47  0.35  103
SLN     David Eckstein    64    95  1   1.9  7.58  0.42  106
PHI     Jimmy Rollins     63    96  2   3.8  7.04 -0.25   97
SEA     Ichiro Suzuki     63    99  1   5.3  9.26  1.56  120
CHN     Jeromy Burnitz    61    83  2  -2.7  6.97 -0.51   93
ANA     Darin Erstad      59    95  0   9.0 11.14  3.05  138
BAL     Brian Roberts     59    83  1  -1.8  8.09 -0.63   93
CHN     Derrek Lee        59    91  1   3.0  9.79  1.16  113

From this you can see that even though Johnny Damon may have taken the extra base upwards of 60% of the time, when considered in his context complete with David Ortiz and Manny Ramirez as hitters coming behind, he actually contributed negative .24 runs and was 2% below average. On the other hand Darin Erstad of those Angels contributed an additional 3 runs with his baserunning and was 38% above average, which incidentally was just slightly more than Chone Figgins contributed (3.02).