First invented by Keith Woolner, Baseball Prospectus defines VORP (Value Over Replacement Player) as the following:
The number of runs contributed beyond what a replacement-level player at the same position would contribute if given the same percentage of team plate appearances. VORP scores do not consider the quality of a player’s defense.
A Deeper Analysis of VORP
The definition provides us with a cursory definition that only scratches the surface of a very meaningful measure for comparing ballplayers against their cohorts sharing the same position. The most important bit of information to glean from this basic definition is that the offensive prowess of a given ballplayer should only be compared against others who play the same position (shortstops should be compared only with shortstops and first baseman with other first baseman). Keep in mind since the degree of difficulty required to play a position such as shortstop or catcher is higher, it is widely assumed fewer ballplayers can athletically handle those duties; therefore lesser aggregate offensive numbers are generated at those positions.
While this is elementary to some, many ignore this fact and opt to make valueless comparisons among certain ballplayers. Derek Jeter’s offense should never be directly compared against Justin Morneau’s production and I will illustrate why later. General Managers focus on building a team that competes positively against other organizations on a position by position basis; VORP is a measure that helps them achieve that end.
So What Exactly is Replacement-Level?
A replacement-level player can generally be defined as a standard minor league call-up (we are not talking about a top prospect here) being paid at the league defined minimum salary. The expectation from the team is that the call-up will offensively perform worse than that of an average major leaguer at the call-up’s particular position. Specifically speaking, replacement-level is benchmarked at 80% of the aggregate offensive production of an average major leaguer. The production I speak of represents the runs produced by a player at the cost of an out. The offensive splits that are used to easily quantify production values against replacement-level are batting average, on-base percentage, and slugging percentage.
A Look Back to the 2006 MVP Race
Two years ago, it all came down to Justin Morneau and Derek Jeter for AL supremacy. Many thought Jeter would finally get his lifetime achievement award (after a 1999 snub), while skeptics felt the perception of a New York bias would hurt him in the voting. As it turned out, Jeter finished second to Morneau who arguably was not even the best player on his own team that year (that distinction went to Joe Mauer). As it turns out, a closer look at the numbers revealed Jeter was vying for more than mere recognition for a decade of Hall of Fame service.
Let’s look at the 2006 splits and analyze how Derek Jeter compared against average and replacement-level major league shortstops:
- .274/.330/.408 (average ML shortstop)
- .219/.264/.326 (replacement-level shortstop)
- .343/.417/.483 (Derek Jeter’s performance at shortstop)
As you can see, Jeter’s jump is quite considerable compared to both replacement-level and average offensive shortstops. This differential made him extremely valuable at his position in 2006 compared to all other ballplayers with respect to their position. In fact his VORP was the highest in the American League at 80.5. Strictly in terms of hitting, this tells us that Derek Jeter was responsible for accumulating 80.5 more runs than a replacement-level shortstop could have for the 2006 New York Yankees. As a point of reference, the 2006 New York Yankees scored 930 runs as a team (making Jeter responsible for producing 8.65% more team runs than a recplacement-level shortstop).
Now let’s see the 2006 splits and analyze how Justin Morneau compared against average and replacement-level major league first basemen:
- .282/.358/.482 (average ML first baseman)
- .226/.274/.386 (replacement-level first baseman)
- .321/.375/.559 (Justin Morneau’s performance at first base)
There is nothing to take away from Morneau’s numbers, as he still produced an outstanding season for the Minnesota Twins (yielding a VORP of 52.0). However, the disparity between Morneau and Jeter is readily apparent. Jeter hit for an average that was +124, had an on-base percentage that was +153, and a slugging percentage that was +157 when compared against replacement-level shortstops. Compare that to Morneau who was +95, +101, +173 when stacked up against replacement-level first basemen.
Steven Goldman of Baseball Prospectus and author of the Pinstriped Bible had this to add:
Jeter’s season is also in the historic ballpark. Few shortstops, including Jeter himself, have hit as well as he did in 2006. The only other year in his inventory that’s as good was 1999. Major league shortstops batted .274/.330/.408 to Jeter’s .343/.417/.483. Big difference. Jeter’s offensive 1999 was probably in the top 10 shortstop seasons ever. The writers missed it. His 2006 wasn’t nearly as good — it merely ranks in the top 30 or 40. That’s where Mauer’s season ranks in the history of catching as well. Without being rigidly scientific about it, Morneau’s 2006 offensive season is probably about the 200th best in the history of first basemen.
The sports writers (who coincidentally vote on the MVP winner from each league) are mired in an age old tradition of assessing a player’s value. Since they cannot watch every game and each player they stick to traditional statistics when the time comes to cast their vote. In this case, there was no surprise in the choice of victor. Morneau was able to drive in 130 runners compared to the 97 driven in by Jeter. Of course Morneau gets the benefit of batting clean-up as opposed to second in the lineup, so his RBI chances are increased. Unfortunately, RBI is a far sexier statistic than VORP.
Nevertheless, unfair player comparisons violate the logic of VORP – players must first rate against their tangible counterparts on a position by position basis. Then one can measure a ballplayer’s VORP relative to other players at different positions, revealing who is more valuable to their team. As Steven Goldman pointed out, Jeter was inside the top 40 of all time offensive seasons for a shortstop, whereas Morneau cracked the top 200 for first baseman. You decide who was worth more.
Please note: this examination was not meant to take anything away from the performance of Justin Morneau in 2006; it was merely used to illustrate the need for a new way of thinking when it comes to baseball statistics. I certainly think it is time the writers all get on board.
Where my Analysis Falls Short
Sadly, my own knowledge is insufficient, and where this primer is lacking most is in the ability to show you the formula for how VORP is actually calculated. We know Jeter was good for 80.5 runs over replacement, but how is that number reached? I hope someone with more knowledge on the subject of sabermetrics can answer that question. I speculate this is a valued bit of information, which is held closely to the vest of its creators.
As it turns out, my initial speculation may in fact be seeded in truth. OTB sports validates my suspicion:
The biggest problem with VORP is that Baseball Prospectus keeps it a proprietary statistic. This is reasonable. Keith Woolner invented it and the information of how to compute it belongs to him. There is a downside. OPS, which is an intuitive statistic, has caught on, whereas VORP remains primarily within the parlance of sabermetricians and their mathematically challenged acolytes. This is changing as more and more writers, enabled by the modern free press of the Internet, comment on the utility of VORP and other modern statistical measures of baseball.
6 Comments
This is interesting.. I still have a few questions though. First, how often does previous data predict future performance? Obviously it’s not going to be perfect, and can’t account for injuries. However, does it form a stronger trend than “traditional” statistics alone?
Second, how respected are these numbers? Obviously they alone will not win Jeter an award, but are careers made and broken by the results of these numbers? Do only select teams really crunch numbers like this, or is it everybody?
Jake, all very good questions, and I will answer to the best of my ability.
Generally speaking VORP is measured on a season by season basis, much like Batting Average, Hits, RBI, Home Runs, and Runs Scored. The advantage sabermetrics (the creators of all these new stats like VORP) gurus boast for this particular statistic, is that VORP is a single stat that serves as a composite for the more traditional statistical measures (BA, Hits, RBI, HR, R). Since it flat out tells you how many runs a player was worth to a team in a given year.
What the people at Baseball Prospectus will then do is take the last three years of a player’s career, crunch the numbers, and project a player’s VORP for the upcoming season accounting for advancing age (which helps you when you are younger and hurts you when you are older) and the home ballpark they play in.
In regards to league wide respect of the numbers, that is a great question. There is a great divide in the sport between old school talent recognition and the new number voodoo brought to us by sabermetrics. Some General Managers (Billy Beane included) live and die by the new methods that have been developed (VORP being one of the valued measures). Other GM’s insist on being formal students of the game and watching film to look for intangibles in a player. Arguing that statistics do not tell the whole story.
Generally speaking, the most successful GM’s like Theo Epstein, Brian Cashman, J.P. Richardi, and Billy Beane (there are many others as well) incorporate both methods into their team building strategies.
The people responsible for reaching the baseball audience (the sports writers) are the most lacking in understanding the evolution of baseball. Little is done on their part to explain how new statistics are changing the game. They may choose to omit this new information bcause frankly, the average fan could careless. I think that is a cop-out since it is their responsibility to explain the game to the best of their knowledge in the simplest of terms. For me, those are the characteristics of a great sports writer.
Not to mention, sports writers vote on all major awards and they vote on what players are inducted into the Hall of Fame. It should be their responsiblity to be aware of what statistics are the most indicitive of a players ability.
Personally, I think there is no substitute for watching a player everyday as the best determinate of their skill on the field. Clearly, it is not possible to watch all ballplayers, therefore it is vital to know what stats best makeup for what your own eyes cannot see. For me, three bits of information tell me a great deal about a ballplayer: their OPS, their VORP, and the position they play.
Figures that the formula for VORP is confidential information. I am not a huge fan of VORP per se (probably because I just don’t know how they get their final number), but I think it is a neat idea. From what I think I understand it is a ratio of their runs scored/batted in to the outs they make on defense and offense. I think VORP is better meant to understand HOW valuable a player is to his team, but not in the whole league; as far as trying to find a replacement. Talking about VORP really allows the fan to see that ‘the grass is not always greener on the other side’. For example, looking at A-Rod, a lot of New York Fans wanted him gone, but when you start looking at who can replace him – the outlook looks glum.
There should be a lot of other intangibles that are looked at when picking the MVP besides stats, such as did the team do well with the player having an amazing year or did that player miss a lot of games due to injury.
VORP is a great tool, but nothing beats a star caliber player that leads his team into the postseason. To me that is MVP worthy.
Rineberg, VORP does not factor defense into the equation at all. It represents the runs produced by a particular player in relation to the outs they accumulate over a season.
Think of it as an exchange rate, with outs being the currency and runs being the product. The best players buy more runs with their outs.
Oh ok I understand. I just thought that defense whether good or bad would be considered in evaluating how irreplaceable a player was.
For defense, zone rating is a measure that is becoming commonplace.
2 Trackbacks
[...] analysts actually explain the concepts of Moneyball and VORP to the casual fan. I have an inclination that they do not quite understand themselves. There is no [...]
[...] fans that want to take a deeper look into how statistics now rule the game, why VORP matters, why On-base Percentage is the mother of all offensive statistics, and what Zone Rating [...]