Sunday, December 27, 2009

timeonice.com

I have finally gotten around to updating the playershots scripts at timeonice.com. What follows is a 'how to' for those interested in using these apps. All data is for even strength only, empty net situations are excluded.

http://timeonice.com/playershots0910close.php?team=EDM&first=20001&last=21230&daniel=5&henrik=71

The word close refers to the score being within one goal in the first or second period, or a tied score in the third period or overtime.

Omit the word close to get the overall numbers, or replace it with tied, lead or trail to generate data for these self explanatory game states. ' Lead' refers to leading in the third period, or leading by more than one goal in the first or second period. 'Trail' is the photo negative of that.

The team can be switched by changing the three character team abbreviation. So replacing EDM with CGY in the above URL would generate the Flames' numbers. A full list of NHL.com play by play abbreviations can be found here.

The URL near the top of the page also outputs the combined data of Smid (5) and Visnovsky (71). This result is shown as a fictional player with the jersey number 99. If you add "&kesler=27" to the end of this URL, the results of player 99 will reflect events that occurred when all three of Smid, Visnosky and Penner were on the ice at even strength, with both goalies in the net, and with the score close. The players can be changed by using different jersey numbers in the URL.

Sunday, December 06, 2009

Gin + gin + gin + vermouth = hockey?

I had originally meant to come home, drunk as an Irishman, and rant. Rant like I haven't ranted since Mike Comrie and the Edmonton Oilers kissed and made up. After all, we're not yet a third into the season and we're already looking at a lottery pick. Try as you will but you can't deceive me with Red Wing own goals or pretty stories involving Shawn Horcoff demanding a chance to shoot.

The fun thing is, I drank gin with a man from BC tonight who is actually a childhood friend of Shawn himself. I rarely bring up hockey around him, for he is distinguished in his own right, but the truth is we both love the game and we're both fans of players who bring it on both sides of the ice. So it is that I know weird things like Horc scored 40 out of his team's 45 goals en route to a peewee championship way back in the day. Truly a "skilled" player at the time.

Anyhoo.

The real drunken rant that I think I should aim for is one, poorly punned enough, in reverence for the work that gets done by the real heavy lifters on this blog. I'll be the first to admit that if Vic, Rivers, and Sunny are the Gretz, Mess, and Coffey of this corner of the internet, I am more of an Adam Graves or Joe Murphy, and since the girlfriend is currently passed out, I might as well spend this time throwing out some praise.

As I said, I had the chance to drink with one of Horc's good friends tonight. But did he, the drunken Irishman that he was, know the truth about Shawn's excellent zoneshift numbers over the last few years? Of course not. Did he know why Zetterberg is more valuable than Lecavalier despite similar boxcars? Again, of course not. Did he know why the hot redhead with the glasses was, for some inexplicable reason, unfathomably sexy? Well, actually, maybe he did. I expect it was obvious.

The inescapable, non sexy redhead truth here is that I have had the good fortune over the last few years to look at hockey through an entirely new set of eyes. I have always been an empirical type (as early as age 12, I spent time counting the amount of days I could spend avoiding a girl before she threw sand in my hair and professed her love for me) and therefore have gravitated to sites like this one. Through the perspectives of Vic, Rivers, Lowetide, Mudcrutch, Dennis, Black Dog, and so many others, I have had the good fortune to look at hockey in a completely new, more understandable light. I think it's worth taking the time to raise a glass (especially since some of you were influential in my choice of glass tonight) . There is fantastic work being done every day by smart hockey people on the internet and I sincerely appreciate the chance to read and absorb it, no matter how rarely (through my own life schedule) I get the chance.

If I ever meet another one among you, I will certainly buy you a beer. Until then, if you are someone who puts genuine thought into the game of hockey and then wanders onto the internet to post about it, please know that I appreciate the time you take. There are many among us, and since I have had about 18 gin martinis in the last 6 hours, I feel it is my place to say Thank You.

Whoop.

Tuesday, December 01, 2009

A Brief Look Into the New Jersey Devils’ Official Shot Totals

The topic of data recording error with regards to Shots On Goal has made for interesting discussion lately. JLikens, in a post at Objective NHL a few months ago, noted a seemingly significant discrepancy in total shots (i.e. shots on goal taken by both teams) in the New Jersey Devils’ home games relative to their road games. Tom Awad over at Puck Prospectus recently wrote an article in which he had similar findings. Vic Ferrari, here at IOF, surmised that official scorers around the league seem to have different definitions of what constitutes a shot on goal versus a shot at goal, but that a difference in home shots at goal versus road shots at goal may be due to an actual strategic effect.

I decided to track shots for a couple of recent Devils games. Far more sampling needs to be done, but I was encouraged to post my findings of even the small sample, so that’s what I’ll do.


11/25/09, Ottawa at New Jersey

MY COUNTS:

Devils Shots: 28 Shots on Goal, 21 Attempts/Blocked, 9 Missed Shots = 58 total shots directed

Sens Shots: 29 SOG, 12 A/B, 10 MS = 51 total shots directed


NHL OFFICIAL COUNTS;

Devils Shots: 21 SOG, 11 A/B, 6 MS = 38 total shots directed

Sens Shots: 25 SOG, 5 A/B, 6 MS = 36 total shots directed


You can see that my totals are pretty far off from the official ones. It could have been a fluke, or I could have just been too generous with what dictates a “shot.” I was fairly meticulous though, liberally pausing and rewinding my dvr to double check anything questionable. (But I did watch the game at 10pm on Thanksgiving Day after drinking Bloody Marys since noon lol.)

I decided to do a road game.


11/27/09, New Jersey at Boston

MY COUNTS:

Devils shots: 38 SOG, 11 A/B, 12 MS = 61 shots directed

Bruins shots: 35 SOG, 17 A/B, 16 MS = 68 shots directed


NHL OFFICIAL COUNTS:

Devils shots: 37 SOG, 7 A/B, 8 MS = 52 shots directed

Bruins shots: 33 SOG, 17 A/B, 8 MS = 58 shots directed


For the game in Boston I was over by ~10 directed shots compared to ~20 directed shots in New Jersey. Again, it could have been a fluke, or I could have been too generous in my recording. Or, frankly, there could be wide discrepancies throughout the NHL on how shots are actually being counted, as well as how they should be counted.

I spoke to a well-known hockey blogger who recently discussed shot counting bias with a fellow who once worked for a minor league hockey team. Apparently the shot counter there was an old-timer who had been doing it for a while and was pretty “set in his ways.” And those ways were…well…debatable.

For the Devils’ next game, 11/28/09 at home against the Islanders, I decided to watch the TV broadcast while simultaneously checking out the NHL Play By Play feed on my laptop. In particular, every time I saw what I thought looked like a shot attempt, I checked to see if and how it was scored officially.

At times I wondered if I was watching the same game as the NHL dude.

Check out this clip from 5:51 remaining in the third period…

[link]

Now, um, have I gone batshit crazy, or is that basically the definition of a “shot”, both at goal, and in this case, on goal? Yet, in this game it was officially classified as neither! The Play By Play feed goes from “Faceoff, 6:15” to “Stoppage of play, 5:51” with no record of anything in between. I also double checked the box score, and Trent Hunter has a big old zero in the shots column for the third period.

Here’s another not-significant-enough-event-to-be-officially-classified-as-anything, from a few seconds later.

[link]

That one’s more debatable. But I showed it to you on purpose for a point I’ll make in a minute. For now I’ll just say this: the puck was directed at the net, had some probability greater than zero of going into the net, and would have been counted as a shot on goal had it gone in. Same shot – sometimes counted as a shot, sometimes counted as nothing.

I could comb through the whole game for examples to post, some more glaring than others, but you get the point.

A few days later, I did the same thing of watching the TV broadcast and NHL Play By Play feed simultaneously for a Vancouver Canucks home game against San Jose. In this case, I was actually pleasantly surprised that almost every event I perceived as a shot directed at net was in fact recorded as some sort of shot attempt (i.e. SOG, A/B, MS).

I’ll wrap this up now with a few editorial comments.

1) I found it quite valuable to partake in the exercise of recording shots at net. I highly recommend it. You get a real sense of how the game works, and you realize just how important it is for a team to be able to even attempt shots.

2) I think shot attempts are maybe the most valuable metric we currently have. There is so much parity in the quality of shooters, goaltenders, and team defenses throughout the league that just attempting a shot and giving your team a chance to have the puck go in is huge.

3) On the latter note – chance. It’s a key word in understanding the importance of shot attempts. Randomness (i.e. luck, i.e. “chance”) is absolutely rampant with regards to goal scoring. We’re talking about 2 or 3 goals being scored on 50 or 60 shot attempts. What do you think constitutes the difference (or most of the difference) between them? Imo it ain’t Ovechkin getting an uncontested breakaway versus Hextall letting in a softy from center ice. Most shot attempts that result in goals, compared to shot attempts that don’t, do so because of the sheer physical randomness subjected upon a small disc of vulcanized rubber being hurled through the atmosphere at a high velocity with several obstacles in its way.

4) Extreme recording error for data like “shot attempts” is pretty pathetic for an enterprise like the National Hockey League. Many of these recorded statistics are used to hand out awards, dole out salaries, and rewrite history books. For fuck’s sake, get a panel of college interns in every city to record data individually, just so you have a few sources to compare/average. The kids would probably work for pizza and beer. :)

5) Consistent and reliable shot attempt data is the most fundamental starting point for analysis imo. It’s more fundamental than scoring chances (and less prone to human bias and inconsistency); though perhaps less fundamental than puck location. While a certain amount of speculation about a player’s intent is unavoidable and necessary, I think it’s better to err on the side of generosity when it comes to recording an event as a shot attempt. I.e., If it’s not an obvious pass, and it’s directed at net, and it has a reasonable probability > 0 of being a goal, it should be recorded as a shot attempt of some kind.

6) Given consistent data, I’m inclined to think all individual and on-ice Sh% and Sv% equations should have shot attempts as the denominator. Before you scoff at the notion of a goalie getting credit for a blocked shot, realize that it’s mostly a matter of semantics. Goalies get penalized all the time for letting in goals on events that often wouldn’t have been recorded as shots in the first place had they not gone in. Having a denominator with significantly less bias is more important (and more insightful) than any other factor. If shooters, goalies, or defenses have the ability to control the number of goals they score or let up in lieu of quantity of shot attempts, it will show up, so long as we have consistent data.