Jul 012014
 

The other day I commented on twitter that I would be happy if the Leafs signed defenseman Mike Weaver because I think he is a defensive defenseman that I think the Leafs could really use. I have thought of Mike Weaver as a premier defensive defenseman for quite some time now. I always seem to get a little flak over it but that’s fine, I can handle it. For example, as a response to my Weaver comment on twitter Eric Tulsky thought it would be prudent to point out a “flaw” in my thought process.

 

And of course, Tyler Dellow never passes up an opportunity to take a jab at me (or anyone who he disagrees with) took the opportunity to re-tweet it.

Now, of course I had thought of responding with a tweet to the effect of “Florida’s save percentage was probably is a bit of a factor in that regression” but I didn’t want to get into a twitter debate at that moment and I was confident I could come up with more concrete evidence. So here is that evidence.

SavePercentageWeaverOnOffIce

The above chart shows the save percentage of Weaver’s team when Weaver is on the ice vs when Weaver is not on the ice including only games in which Weaver has played in (i.e. it is better than just using team save percentage for that season and also allows us to combine his time in Florida and Montreal last season). As you can see, there has only been one season in the last 7 in which his team had a worse save percentage when he is on the ice than not. That is reasonably compelling evidence. It’s difficult to say what happened that season but his main defense partners were a young Dmitry Kulikov and Keaton Ellerby so maybe that was a factor. An investigation of Kulikov’s and Ellerby’s impact on save percentage over the years may help us identify why Weaver slipped that year. It could have been a nagging injury as well. Or, it could just be randomness associated with save percentage.

Regardless of the “reason” for the slide in 2011-12 it is pretty difficult to argue that there has been significant “regression” the past 3 seasons as Tulsky and Dellow so eagerly wanted to point out as the past 2 seasons Weaver has seemingly had a significant positive impact on his teams save percentage. Since I made that statement there has been one seasons of “regression” so to speak and two seasons in support of my claim. I guess that means it is 2-1 in my favour. It continues to appear that Weaver is a good defenseman who can suppress shot quality against.

Another defenseman I have identified as a defenseman who possibly can suppress opposition save percentage is Bryce Salvador. Here is Salvador’s on/off save percentage chart similar to Weaver’s above (2010-11 is missing as Salvador missed the season due to injury).

SavePercentageSalvadorOnOffIce

Salvador’s on-ice save percentage has been better than the teams save percentage every year since 2007-08. Regression? Doesn’t seem to be.

To summarize, there are a lot of instances where if we simply do a correlation of stats from one year to the next or  make observations of future performance relative to past performance we see the appearance of regression. In fact, the raw stats do in fact regress. That doesn’t necessarily mean the talent doesn’t exist, just that we haven’t been able to properly isolate the talent. The talent of the individual player is only a small factor in what outcomes occur when he is on the ice (a single player is just one of 12 players on the ice during typical even strength play) so it is difficult to identify without attempting to account for these other factors (quality of team mates in particular).

Possession and shot generation/suppression is important, but ignore the percentages at your peril. They can matter a lot in player evaluation.

 

Jun 122014
 

The rumour is out there that Sunny Mehta has been hired as Director of Hockey Analytics of the New Jersey Devils (if true, a big congrats to Sunny). This sparked some twitter discussion about the Devils and analytics and Devils defensemen including Bryce Salvador.

I have been a bit of a fan of Salvador, at least statistically, though clearly there are a lot of Devils fans that do not like him and I think it is because of a focus on corsi. One person tweeted me an image of Salvador’s corsi rel % suggesting it was “pretty ugly”. While maybe true the game isn’t about Corsi it is about goals. Here is what I know about Salvador. In 5v5close situations he led the Devils defensemen in on-ice save percentage last season, the season before, and the season before that. He missed 2010-11 due to injury but in 2009-10 he was second best trailing only Andy Greene, his regular defense partner. Either he is extremely lucky (every year) or he is doing something right.

Lets look at this a different way. Over the past 3 seasons Bryce Salvador has had the third best 5v5close save percentage in the league when he is on the ice despite the Devils ranking 23rd in team save percentage. The two players ahead of him play for Boston (Dougie Hamilton) and Los Angeles (Willie Mitchell) who have significantly better goaltending (3rd and 8th best 5v5close save percentages over past 3 seasons) and again, they played in front of far better goaltending.

In February 2012 I wrote an article attempting to quantify a defenders effect on save percentage and in it I identified Salvador as one of the best defensemen at boosting his teams save percentage. In the 2 seasons since he has done nothing but support that claim.

So, what does this all mean? Well, it takes a player who had a team worst 15.9 CA/20 in 5v5close situations this past season to a team best 0.49 GA/20.  Over the past 3 seasons only Dougie Hamilton (Boston), Willie Mitchell (Los Angeles) and Alec Martinez (Los Angeles) have seen goals scored against them at a lower rate than Bryce Salvador.

I know the majority of people are on the corsi bandwagon these days and some will dismiss any argument that runs counter to it but I think the evidence is clearly on Salvador’s side here. All evidence suggest he is really good as suppressing opposition shot quality and in turn suppressing the number of goals scored against the Devils. If I were the new Director of Hockey Analytics for the Devils I wouldn’t be recommending getting rid of Salvador.

 

Sep 152011
 

Over on Pension Plan Puppets there was a brief discussion of some of the top defensive defensemen and I suggested that Mike Weaver has to be considered among the top few defenders in the NHL.  The response was generally along the lines of ‘Mike who?’ and then followed with “he only looks good because he plays in front of Vokoun who may be the best goalie in the NHL.”  My thoughts on Vokoun being over rated aside, the numbers really do support Weaver as being a premiere level defensive defenseman.  Let’s look at some Mike Weaver numbers.

Over the past 4 seasons Mike Weaver played one season in Vancouver, 2 seasons in St. Louis and last season he was in Florida.  During that time there have been 173 defensemen who have played >1500 5v5 close (within 1 goal in first or second period or tied in third period) minutes and of those 173 defensemen Weaver ranks fourth in on ice goals against per 20 minutes of ice time.  He only trails Bryce Salvador, Sean O’Donnell and Paul Martin (3 other under rated defenders IMO).  Ranking 4th is a pretty good argument for why he is a great defender.  So what about the typical excuses for why he might rank so highly?

1.  Goalies make him look good.  Not really.  In the past 4 years he has played 2455:08 minutes of 5v5close ice time, 798:24 (32.5%) in front of Chris Mason, 587:45 (23.9%) in front of Vokoun, 390:58 (15.9%) in front of Luongo, 297:47 (12.1%) in front of Clemmensen, 185:04 (7.5%) in front of Conklin and some time in front of a few other lesser goalies.  At best you can argue he has played 45% of his time behind premiere level goalies (Vokoun and Luongo) with the remaining 55% behind second tier starters (Mason) or third tier starters and backups (Conklin, Clemmensen, etc).  In his year in Vancouver, the Canucks ranked a solid 7th in team goals against average but his 2 years in St. Louis the Blues ranked 12th and 11th and last year the Panthers ranked 14th so while he hasn’t played on any bad defensive teams he hasn’t played on any elite defensive teams either.  It’s difficult to make the case he has had an unusually significant benefit from playing in front of elite goalies or on elite defensive teams.

2. He Plays Easy Minutes.  Not really.  Over the past 4 seasons he ranks 45th of 173 defensemen with 34.1% of his face offs in the defensive zone and last season he started 36.9% of the time in the defensive zone or 21st highest of 157 defensemen with 500 5v5close minutes.  Over the past 4 seasons his opposition goals for per 20 minutes ranks 31st of 173 defensemen so he is seemingly playing against quality offensive forwards.  Last season the forwards he played most against were Ovechkin, Backstrom, Knuble, St. Louis, and Stamkos so yeah, that’s pretty good competition.  Over the past 2 seasons only Chris Phillips and Jay Bouwmeester have played more time on the 4v5 penalty kill than Weaver.  He is trusted playing tough minutes against top competition so the easy minutes argument is not valid.

While we are at it, Mike Weaver is another example why I do not like corsi/fenwick stats.  While Weaver has the 4th best on-ice 5v5close goals against per 20 minutes, he ranks a far less impressive (though still a little above average) 47th in fenwick against per 20 minutes.  The main reason why Weaver is so good defensively is he suppresses shot quality really well.  He ranks 3rd in shooting percentage against (or save percentage) while he is on the ice and he has been consistently above average over the past 4 seasons (6th of 176 in 2007-08, 63rd of 147 in 2008-09, 13th of 154 in 2009-10 and 22nd of 157 in 2010-11).  Three of the past 4 seasons he has been a top 25 defenseman in terms of shooting percentage against and the fourth and worst season he was still in the top half.  Sorry, but there is no ‘regressing to the mean’ there.

Mike Weaver is a premiere, and vastly under rated and under paid ($900,000), defensive defenseman.