Friday, May 1, 2009

Scoring Chances - Home v. Road

These are the home and road splits for the entire season. Thanks again to Dennis for counting the chances game after game and giving us some really interesting things to work with. His individual game summaries can be found here. Vic Ferrari has also done some work on scoring chances showing how Dennis marked his team consistently with how he marked the other guys.

When I took a look at the home and road splits at the halfway point there wasn't nearly as much separation between the two sets of data as I would have expected. Let's see if things have changed with a full season's worth of data.

(For those unfamiliar with the metric a player is awarded a chance any time someone on the ice has a chance to score. He is awarded with a “chance for” if someone on his team has a chance and awarded with a “chance against” if someone on the opposing team has a chance to score. The results are broken down into three game states, EV (even strength), PP (Power Play) and SH (Short-Handed). The players are organized according to their jersey numbers.)

Home Games One Through Forty-One, October 12 to April 10
Missing Games 40 vs San Jose and 81 vs Calgary
21 = Potulny and 21* = Kotalik

Road Games One Through Forty-One, October 15 to April 11
Missing Games 22 at St. Louis, 33 at Vancouver and 82 at Calgary
21 = Potulny and 21* = Kotalik

These results start show the advantage of playing on home ice more than the mid-season results. No one does significantly better on the road than they do at home (Visnovsky's chance differential is 12 better on the road than it is at home which leads the team). This should put to bed any idea that the Oilers played better on the road than they did at home, an idea further buttressed by their goal differential even if it doesn't show up so much in the record (18-17-6 at home and 20-18-3 on the road). The reason for the discrepancy looks like one part shootout records and one part luck. On to some of the interesting totals:

Nilsson - -7 at home and -6 on the road. By no means are these great totals but they do speak to the fact that MacTavish was able to shelter the players he wanted to shelter both at home and on the road. Nilsson needs to be able to win the chance battle if he's being sheltered, so it's fair to say his lack of productivity is one reason the Oilers didn't play in May. The same can be said of:

Gagner - +7 at home and -5 on the road. Gagner improved a lot this season but he was mostly getting easy minutes against mid-level competition. For this team to be a winner Gagner is going to need to outchance big in these minutes. The lack of difference between home and road results again speak well of MacTavish I'd say. Well, either that or he's terrible at matching lines but you'd think other teams would be taking advantage of the young guys unless there's no reason to wait for them...

Moreau - -34 at home and -62 on the road. There's no reason to wait for them. Moreau plays a hard style so he's probably a little bit "tougher to play against" in that sense but his results are terrible. He does better at home than he did on the road which leaves me to wonder if MacTavish may have sheltered him a bit more at home. If only Behind the Net split data into home and road splits! I also have this question of:

Hemsky - +20 at home and -15 on the road. Almost all of this difference is felt in the second half since his home and road results were about the same at that time (and both were good). The difference is especially striking when compared to Horcoff whose results were much closer together (+5 at home and -3 on the road) in spite of receiving the more difficult minutes.

Grebeshkov - +38 at home and -13 on the road. Those are some pretty different numbers. I don't think it was much to do with the Visnovsky effect because (1) Visnovsky only played two more home games than road games and (2) Visnovsky actually had better results on the road than at home. A deeper analysis might pick up more influence but those preliminary points suggest that either Grebs was a much better player at home or MacTavish was able to get him more favourable match-ups more often. Another thing pointing in that direction is:

Gilbert - +13 at home and -37 on the road. Again, quite different stories but not as much to like as with Grebs. With a d-man likely on the way out this summer these guys won't be able to avoid the toughest home minutes if Souray or Visnovsky is on the way out. Hopefully they can rise to that challenge.


Vic Ferrari said...

Good stuff, thanks Scott.

Just to level the playing field, it might be a good idea to look at 'scoring chance percentage'

So, at home, Grebs would be 55% [220/(220+182)] and on the road he would be 48%. And so on for everyone.

That does seem like a big swing for him, I would think a 2 or 3% swing would be more normal. Though him and Gilbert got off to a rough start playing together this year, and ost of the early gaes were road games, so that probably accounts for a big chunk of it.

Scott said...

Thanks Vic. Putting things into scoring chance percentage is a good suggestion.

As for Grebs, it's not just in the first few games. Second half results only leave him at 47.8% on the road and 53.8% at home. The spread is less pronounced than the first half but it's still a sizeable gap.

Vic Ferrari said...

Good point. Gilbert too doesn't look to have rebounded fully in terms of road scoring chances.

I think you're probably right that there was an element of shletering from Huddy there. It's generally easier to get the D matchups on the road than the forward matchups, though. So I'm surprised it's that significant.

Along a similar vein:
The EV home/road points and EV +/- for previous seasons are probably listed somewhere. It would take a while for the bounces to even out, maybe three seasons, but I would bet that if you looked at Marchant and Weight over the period of 3 to 4 years that Marchant had the checking gig and Weight was on the roster ... I bet that the swing from home and road results is big for Weight, and probably not much at all for Marchant.

Scott said...

You're right about Gilbert. I think there's still a gap between 4% and 5% for his second half (I don't have my chart on this computer so I'm just going from memory). If it's true that the G&G pair was getting somewhat sheltered at home it helps to put the year Staios had in context. He's a real strange cat. His first half of the year against nobodies he was getting mowed down, but then he moves up to play the toughs and there's no discernable change in his chance rate. Now, maybe that's because you can only go so low. I think it's probably more to do with his style and the effects of defencemen in general. Unless you're skating miles and lugging the puck I'm not so sure the defencemen can control the chance rate that much. It probably hinges a bit more on the forwards. People talk quite a bit about the difficulty of minutes in terms of starting position and quality of opponents but I really do wonder if quality of teammates gets ignored a bit too much.

The Weight/Marchant thing makes sense intuitively. It would be interesting to check it out.