hometeam
01-07-2013, 08:27 PM
http://harvardsportsanalysis.wordpress.com/2012/05/25/equally-inaccurate-an-analysis-of-mel-kiper-jr-and-todd-mcshays-draft-rankings/
Equally Inaccurate: An Analysis of Mel Kiper Jr. and Todd McShay’s Draft Rankings
Posted on May 25, 2012 by harvardsportsanalysis
By Kevin Meers and Scott Sherman
Conan vs. Leno. Jack Shephard vs. John Locke. Seinfeld vs. Newman. Over the years, hundreds of great rivalries have come to dominate our television screens. But to sports fans, none of those individual competitions are quite as captivating as the one between ESPN’s two draft gurus: Mel Kiper Jr. and Todd McShay.
There are many iconic hairstyles in the National Football League. Brett Keisel’s lumberjack beard. Troy Polamalu’s bodacious curls. Clay Matthews’ scintillating golden locks. But among the most distinct looks is that of Kiper, whose hair, glasses, and those squinted eyes are one of the signature images of the NFL draft. Every year, he and his fellow heavyweight, the former University of Richmond waterboy McShay, slug it out on millions of television screens in the months leading up to the draft a dramatic attempt to display their expertise. But which of these two titans is a better judge of talent? This post sought to answer that question.
To compare the success rates of the two gurus, we collected the rankings of the Top 25 players in each year’s draft from 2006 (when McShay joined ESPN) through 2010. Kiper’s rankings were determined by his final “Big Board” before each year’s draft, while McShay’s were determined via Scouts Inc.’s final Top 25 (McShay runs Scouts Inc.). We then compared each player’s ranking to their actual performance ranking in their draft class (performance here is approximated by Career Approximate Value). As an example, Kiper ranked Julius Peppers as the best player in the 2002 NFL Draft, and that prediction proved to be dead on, as 10 years later Peppers has the highest CAV of any player from the ’02 draft. While we would have preferred to use the ranks of all players drafted, Kiper only releases his top 25 prospects on his “Big Board,” which severely limited sample size. Nonetheless, here’s what we found:
http://harvardsportsanalysis.files.wordpress.com/2012/05/table2.png?w=559
As the chart above shows, Kiper and McShay have proven to be equally inefficient judges of talent over the past five years. Neither expert’s rankings were a particularly good predictor of how a player would perform compared to the rest of his class. In fact, the average errors listed above suggest that the gurus’ rankings are off by around 35 spots when compared to the player’s actual performance. In other words, a player Kiper or McShay ranked as the 15th-best player in the draft is most likely to actually have been the 40th-best based on CAV to this point in their careers. The root mean square errors (RMSE) imply that Kiper is very slightly less prone to extreme errors than his ESPN counterpart, but that difference is not significant. RMSE severely punishes large errors, so having a comparatively lower RMSE implies that one makes fewer huge errors. However, like the average errors, the RMSE for each scout is enormous.
Indeed, when looking at the lists themselves, it is clear that both Kiper and McShay have, like all draft experts, been prone to extreme hits and misses when compared to the other. In 2006, both had future busts Matt Leinart, A.J. Hawk, Vince Young, and Michael Huff ranked in their Top 10s. But McShay was wise enough to include future All-Pro center Nick Mangold in his Top 25, while Kiper instead opted for Jason Allen. The following year, McShay found more success by ranking Darrelle Revis tenth overall, but the Island himself was nowhere to be found on Kiper’s Big Board. Also that year, both Kiper and McShay smartly pegged Calvin Johnson, Adrian Peterson, and Joe Thomas as three of the four top players in the draft, but both also had JaMarcus Russell and Brady Quinn in their top sevens.
In 2008, Kiper wisely ranked future bust Derrick Harvey 23rd—McShay had him 11th—but Kiper had fellow pass-rushing disaster Vernon Gholston 7th, compared to 15th for McShay. In 2009, both had the bust triumvirate of Aaron Curry, Michael Crabtree, and Jason Smith in their top four, but Kiper pegged Matthew Stafford at No. 3 while McShay had him at No. 7. McShay, however, wisely had both Clay Matthews and Hakeem Nicks in his Top 25, while Kiper had neither (but did, unlike McShay, include Percy Harvin). Finally, in 2010, Kiper, unlike McShay, smartly deemed Ndamukong Suh a better prospect than Gerald McCoy, but that success was immediately negated by his ranking of Jimmy Clausen at No. 4 overall (McShay, to his credit, did not feel Clausen was a top 25 talent).
Clearly, then, both “experts” have been both on-point and wildly off-base with their draft predictions over the past few years. On the whole, neither’s rankings are very accurate. If a player is listed in the Top 25 by either scout, that players will, on average, be in the top forty or sixty players from their draft class, but he is absolutely not guaranteed to be one of the very best players from his year. Furthermore, none of the differences between the average errors of Kiper and McShay are statistically significant: the differences between them are likely more due to luck than actual skill. In other words, you could take Kiper’s “Big Board” or McShay’s Top 25 and ask any random person to put them in any random order, and on average, that person’s rankings will be about as accurate as predicting future NFL success than any of ESPN’s two experts.
Of course, this study was limited by its sample size, as we’d have a fair better chance of really determining who was more accurate if Kiper and McShay both ranked every player in the draft (which only Scouts Inc. does; Kiper merely publishes his Top 25). But the nearly-equal numbers in the table above suggest there is not much of a difference between either’s ability to form an accurate Top 25. Of course, predicting NFL success—as it is in any sport—is extremely difficult, and it’s certainly possible that Kiper and McShay are statistically more accurate than any of the dozens of other websites that publish draft rankings each year. Since player rankings tend to be generally similar, it’s likely all such sites would be prone to a number of mistakes. But to determine whether such errors were as significant as those made by Kiper and McShay, future research should compare ESPN’s two gurus success rate to that of their lesser-known counterparts around the web. Until then, the best we can say is that neither Kiper or McShay is extraordinarily good at what they are paid to do, or even better than the other at doing it.
This article specifically targets McShay and Kiper, but it got me thinking about whether any so called draft experts knew shit about anything. Do they know more than me and you?
Are there any other examples or data on whether any draft expert or non-expert actually gets it right consistently?
So picking a QB who is 'ranked' at X spot in the first round, but not 1st if he is the best guy out there is stupid based on what? Mel Kipers big board? Get real. Nobody knows shit!
http://25.media.tumblr.com/tumblr_mb9xji5XwJ1rge74zo1_500.jpg
Geno for president
Equally Inaccurate: An Analysis of Mel Kiper Jr. and Todd McShay’s Draft Rankings
Posted on May 25, 2012 by harvardsportsanalysis
By Kevin Meers and Scott Sherman
Conan vs. Leno. Jack Shephard vs. John Locke. Seinfeld vs. Newman. Over the years, hundreds of great rivalries have come to dominate our television screens. But to sports fans, none of those individual competitions are quite as captivating as the one between ESPN’s two draft gurus: Mel Kiper Jr. and Todd McShay.
There are many iconic hairstyles in the National Football League. Brett Keisel’s lumberjack beard. Troy Polamalu’s bodacious curls. Clay Matthews’ scintillating golden locks. But among the most distinct looks is that of Kiper, whose hair, glasses, and those squinted eyes are one of the signature images of the NFL draft. Every year, he and his fellow heavyweight, the former University of Richmond waterboy McShay, slug it out on millions of television screens in the months leading up to the draft a dramatic attempt to display their expertise. But which of these two titans is a better judge of talent? This post sought to answer that question.
To compare the success rates of the two gurus, we collected the rankings of the Top 25 players in each year’s draft from 2006 (when McShay joined ESPN) through 2010. Kiper’s rankings were determined by his final “Big Board” before each year’s draft, while McShay’s were determined via Scouts Inc.’s final Top 25 (McShay runs Scouts Inc.). We then compared each player’s ranking to their actual performance ranking in their draft class (performance here is approximated by Career Approximate Value). As an example, Kiper ranked Julius Peppers as the best player in the 2002 NFL Draft, and that prediction proved to be dead on, as 10 years later Peppers has the highest CAV of any player from the ’02 draft. While we would have preferred to use the ranks of all players drafted, Kiper only releases his top 25 prospects on his “Big Board,” which severely limited sample size. Nonetheless, here’s what we found:
http://harvardsportsanalysis.files.wordpress.com/2012/05/table2.png?w=559
As the chart above shows, Kiper and McShay have proven to be equally inefficient judges of talent over the past five years. Neither expert’s rankings were a particularly good predictor of how a player would perform compared to the rest of his class. In fact, the average errors listed above suggest that the gurus’ rankings are off by around 35 spots when compared to the player’s actual performance. In other words, a player Kiper or McShay ranked as the 15th-best player in the draft is most likely to actually have been the 40th-best based on CAV to this point in their careers. The root mean square errors (RMSE) imply that Kiper is very slightly less prone to extreme errors than his ESPN counterpart, but that difference is not significant. RMSE severely punishes large errors, so having a comparatively lower RMSE implies that one makes fewer huge errors. However, like the average errors, the RMSE for each scout is enormous.
Indeed, when looking at the lists themselves, it is clear that both Kiper and McShay have, like all draft experts, been prone to extreme hits and misses when compared to the other. In 2006, both had future busts Matt Leinart, A.J. Hawk, Vince Young, and Michael Huff ranked in their Top 10s. But McShay was wise enough to include future All-Pro center Nick Mangold in his Top 25, while Kiper instead opted for Jason Allen. The following year, McShay found more success by ranking Darrelle Revis tenth overall, but the Island himself was nowhere to be found on Kiper’s Big Board. Also that year, both Kiper and McShay smartly pegged Calvin Johnson, Adrian Peterson, and Joe Thomas as three of the four top players in the draft, but both also had JaMarcus Russell and Brady Quinn in their top sevens.
In 2008, Kiper wisely ranked future bust Derrick Harvey 23rd—McShay had him 11th—but Kiper had fellow pass-rushing disaster Vernon Gholston 7th, compared to 15th for McShay. In 2009, both had the bust triumvirate of Aaron Curry, Michael Crabtree, and Jason Smith in their top four, but Kiper pegged Matthew Stafford at No. 3 while McShay had him at No. 7. McShay, however, wisely had both Clay Matthews and Hakeem Nicks in his Top 25, while Kiper had neither (but did, unlike McShay, include Percy Harvin). Finally, in 2010, Kiper, unlike McShay, smartly deemed Ndamukong Suh a better prospect than Gerald McCoy, but that success was immediately negated by his ranking of Jimmy Clausen at No. 4 overall (McShay, to his credit, did not feel Clausen was a top 25 talent).
Clearly, then, both “experts” have been both on-point and wildly off-base with their draft predictions over the past few years. On the whole, neither’s rankings are very accurate. If a player is listed in the Top 25 by either scout, that players will, on average, be in the top forty or sixty players from their draft class, but he is absolutely not guaranteed to be one of the very best players from his year. Furthermore, none of the differences between the average errors of Kiper and McShay are statistically significant: the differences between them are likely more due to luck than actual skill. In other words, you could take Kiper’s “Big Board” or McShay’s Top 25 and ask any random person to put them in any random order, and on average, that person’s rankings will be about as accurate as predicting future NFL success than any of ESPN’s two experts.
Of course, this study was limited by its sample size, as we’d have a fair better chance of really determining who was more accurate if Kiper and McShay both ranked every player in the draft (which only Scouts Inc. does; Kiper merely publishes his Top 25). But the nearly-equal numbers in the table above suggest there is not much of a difference between either’s ability to form an accurate Top 25. Of course, predicting NFL success—as it is in any sport—is extremely difficult, and it’s certainly possible that Kiper and McShay are statistically more accurate than any of the dozens of other websites that publish draft rankings each year. Since player rankings tend to be generally similar, it’s likely all such sites would be prone to a number of mistakes. But to determine whether such errors were as significant as those made by Kiper and McShay, future research should compare ESPN’s two gurus success rate to that of their lesser-known counterparts around the web. Until then, the best we can say is that neither Kiper or McShay is extraordinarily good at what they are paid to do, or even better than the other at doing it.
This article specifically targets McShay and Kiper, but it got me thinking about whether any so called draft experts knew shit about anything. Do they know more than me and you?
Are there any other examples or data on whether any draft expert or non-expert actually gets it right consistently?
So picking a QB who is 'ranked' at X spot in the first round, but not 1st if he is the best guy out there is stupid based on what? Mel Kipers big board? Get real. Nobody knows shit!
http://25.media.tumblr.com/tumblr_mb9xji5XwJ1rge74zo1_500.jpg
Geno for president