tag:blogger.com,1999:blog-4949598516429271901.post6853748752519912766..comments2024-03-09T16:31:23.329-04:00Comments on Hockey Historysis: Point Allocation on DefenceIain Fyffehttp://www.blogger.com/profile/10700943806242207382noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-4949598516429271901.post-90559189666568118772012-01-04T23:51:56.920-04:002012-01-04T23:51:56.920-04:00Alright, I can do a quick post using the '26 S...Alright, I can do a quick post using the '26 Senators as an example. Any system like this will only be able to do so much - players on good defensive teams will always be subject to overration of defensive values, which is why looking at careers, or at least blocks of years, is important. But it looks like I do a better job than Hockey Reference. It's all about the fudge.Iain Fyffehttps://www.blogger.com/profile/10700943806242207382noreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-44757809232313298492012-01-04T21:46:25.437-04:002012-01-04T21:46:25.437-04:00P.S. If you want to see what I mean, check out th...P.S. If you want to see what I mean, check out the defensive ratings of the aforementioned Senators either at WhatIfSports.com, or Defensive Point Shares at Hockey-Reference.com.<br /><br />http://www.hockey-reference.com/teams/OTS/1926.htmlRobert Vhttp://www.hockeyabstract.comnoreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-8429185447386864372012-01-04T21:44:15.187-04:002012-01-04T21:44:15.187-04:00Ok the 1925-26 Ottawa Senators. Hec Kilrea, Ed Go...Ok the 1925-26 Ottawa Senators. Hec Kilrea, Ed Gorman, Frank Finnigan, John Duggan and Alex Smith might all look like the best defensive players in history for no other reason than they played non-offensive roles on the most outstanding defensive team in history.<br /><br />If you had some outstanding defensive players, and a handful of replacement-level players, how do you avoid the replacement-level guys getting credit for the contributions of the outstanding (other than the two methods already discussed).<br /><br />To avoid my blathering on in the comments section here, can you just show me by touching on the 1925-26 Senators (or a suitable alternative) in an upcoming piece?Robert Vhttp://www.hockeyabstract.comnoreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-81762999104707163042012-01-04T20:29:55.829-04:002012-01-04T20:29:55.829-04:00I should say, though, that in some sense defensive...I should say, though, that in some sense defensive replacement level is built into Point Allocation, but at the team level. The Marginal Goal basis of the system means that only above-replacement-level value is allocated to the players.<br /><br />I think your suggestion has merit, though. I think PA takes care of some of this stuff at the team level.Iain Fyffehttps://www.blogger.com/profile/10700943806242207382noreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-33141782024359457372012-01-04T20:25:18.342-04:002012-01-04T20:25:18.342-04:00I haven't done PA calcs for 2008/09 yet, but t...I haven't done PA calcs for 2008/09 yet, but the modern version of the system should avoid the AJIA trap by looking at ice time, as you suggest, and also by regressing a player's individual plus-minus significantly to the mean. I don't have a lot of faith in +/- by itself, especially for a single player-season (or half-season in this case).<br /><br />Given his lack of PP time, Johnson's scoring rate seems to be pretty decent. The PA system takes that fact, looks at his low ice time, and figures he's not good defensively, which is what you're after, I think.<br /><br />But why are you polluting my precious history blog with this dirty modern stuff? Around here, Aaron Johnson hasn't even happened yet!Iain Fyffehttps://www.blogger.com/profile/10700943806242207382noreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-61688354039591628472012-01-04T17:59:22.297-04:002012-01-04T17:59:22.297-04:00Take a look at Aaron Johnson as an example.
Study...Take a look at Aaron Johnson as an example.<br /><br />Studying his career it's obvious that Aaron Johnson is an adequate 3rd-pairing D-man.<br /><br />However, in 2008-09 he played on the ridiculously powerful Chicago Blackhawks and was +19 in 38 games - best on the team on a per-game basis.<br /><br />As a consequence every measurement out there rated him very highly defensively.<br /><br />There are two ways to avoid falling into the "Aaron Johnson is awesome" trap.<br /><br />1. The idea of looking at a player's career before assigning defensive points, which is why I'm intrigued by your idea. Even a quick glance tells you that Aaron Johnson wasn't responsible.<br /><br />2. Looking at his ice-time. He played just 14:09 per game. He was obviously a replacement-level 3rd-liner playing minimal minutes while the real defenders rested. <br /><br />My proposal: figure out the replacement-level amount of ice-time at each position, and award defensive shares only for all ice-time in excess of that replacement-level that can't be explained by his offensive contributions, and penalize him for every minute he comes up short.<br /><br />What do you think?Robert Vhttp://www.hockeyabstract.comnoreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-18143810827424175702012-01-04T17:10:07.175-04:002012-01-04T17:10:07.175-04:00Rob:
1. Players earn defensive points based (part...Rob:<br /><br />1. Players earn defensive points based (partly) on their ice time per game, so a goon will get very little. Not necessarily zero, as you suggest, but low enough to be effectively zero in most cases.<br /><br />2. That's possible. The penalty ajustment I'm using is quite conservative, so I don't think it would make a significant difference except in the most extreme cases.<br /><br />3. I assume you mean the fudge factor I'm talking about here - I only use that for historical PA calculations, which uses a different system than I use for modern stats. Since the great expansion we have ice time information that we don't have before, and use that to get a better idea of that player's defensive abilities. The fudge is a purely subjective one, based on the player's defensive reputation, and is used to avoid shortchanging players due to there being no such thing as individual defensive stats from their era.<br /><br />4. The (modern) Point Allocation system does not make a 1:1 adjustment to effective ice time based on offence, so great offensive players are not assumed to be terrible defenders to begin with. It also considers such things as PK time and total ice time in the calculations.Iain Fyffehttps://www.blogger.com/profile/10700943806242207382noreply@blogger.comtag:blogger.com,1999:blog-4949598516429271901.post-32204336217574282342012-01-04T15:26:48.859-04:002012-01-04T15:26:48.859-04:00I've always loved the concept behind defensive...I've always loved the concept behind defensive point allocations. Questions:<br /><br />1. How about a minimum level of ice-time to get defensive point allocations? If a player is getting depth-line minutes only and producing no marginal offense, isn't it reasonable to assume he's producing no marginal defense either? In fact, if he's playing less than depth-line minutes (goon) he should get negative defense.<br /><br />2. If a player takes a lot of penalties and yet gets a lot more ice-time than his offense justifies, doesn't that mean his defense is even better than an equivalent player who doesn't take penalties? You know, that a coach would use him even though he costs them so many power play goals.<br /><br />3. I'm intrigued at the idea of re-adjusting a player's defensive point allocations based on his career (e.g. Aaron Johnson's time in Chicago). How is that calculated, exactly - obviously some sort of recursive procedure?<br /><br />4. I'm still intrigued by players like Pavel Datsyuk and Martin St. Louis who could earn their ample ice-time both offensive and defensively. How do you avoid short-changing great two-way players, whose ice-time appears to be explained by offensive contributions?Robert Vhttp://www.hockeyabstract.comnoreply@blogger.com