How much "advantage" truly is HCA?

[chumdawg]

I had a discussion with LRB in another thread about whether the Mavericks have performed "much more poorly" this year than they did the previous three. The discussion narrowed down to two issues: won/loss record and the corresponding playoff seeding.

I wondered how reliable these two factors truly are as indicators of a team's potential for success in the playoffs. I am of the opinion that HCA is generally overrated. The stats bear out that the home team wins 75% to 80% of all playoff series. However, to believe that the home team is that likely to win *any* series would be to commit a misplaced causality sort of logical fallacy.

In other words, most of those series were won by the better team...and having the home court is *not* in itself what caused the team to win. Surely the great majority of those series would have been won by the same team if the HCA had been reversed. Simply put, 1 and 2 seeds are going to beat 7 and 8 seeds most every time, no matter where the games are played.

But what about the cases where the two teams' won/loss records are pretty close? Is the "better" team more likely to win? Is the team with HCA more likely to win? Is the "better" team always the team with the best won/loss record? If one team is 53-28 and the other team is 52-29, is there really a big difference between the teams? Is it possible that the lower seeded team matches up well with the higher seeded team, and not having HCA is not a big enough disadvantage to prevent the lower seeded team from having the best chance to win the series?

Obviously, teams that are separated by a game or two in the win column are very close to each other. So at what point does won/loss record start to reflect a real difference between the teams? Three games? Four? Five? More?

The Mavs are currently sixth in the conference, but only five games separate them from the best record in the West. So I decided to use a won/loss differential of five games and research the data from the last few years to see if the higher seeded team truly has a major advantage based on won/loss record and having HCA.

Using the last four years as a sample, I found eleven first-round series that were played between two teams whose win totals were within five games. In those series, the team with HCA went 4-7. The actual games went 26-21 in favor of the home team, but higher seeded team won only four series. That would seem to be pretty remarkable evidence that in the first round, the higher seeded team stands no real advantage in a close series.

Of course, most of those were five-game series, before the rule change. But I'm not sure how much that changes things.

Another thing to note is that HCA only becomes an advantage to the higher seeded team if the series goes the distance. Anything less, and the series is played on even terms. Of the eleven series mentioned above, only one went the distance (five games). And surprisingly, the road team won.

Now, looking at the last four years gives a pretty small sample. But since the inception of the current sixteen-team format in 1984, the 3 and 4 seeds are a combined 173-141 over the 5 and 6 seeds, for a 55% winning clip. Not an overwhelming advantage. Also, I don't know how many of those series featured teams with close won/loss records.

In the second round, the picture wasn't near as rosy for the lower seeded team. There were ten series that fit the five-game-difference parameter, and the home team won eight of them. The games were 33-20 in favor of the home teams. The home court advantage did come into play more here, though. Four series went the distance, and the home team won three.

In the conference finals, things were absolutely even between two teams whose records were within five games. There were six such series, and they split 3-3. The games were split 17-17. Two series went the distance, and they were split 1-1. No real apparent advantage to having the home court.

We'd need a larger sample to make any firmer conclusions about how "up against it" the Mavs are thanks to owning the six seed (if that stands). But I believe there is no reason to say that the seed itself rules them out of anything. If they match up better than their opponent does, they should have plenty of chance to win the series.

Another thing to note when asking whether the seed in itself indicates that the Mavs have far underperformed this year as opposed to the last three is the relative strength of the conference. This is a remarkably deep year. If the Mavs can get to 53 wins this year (and with the new Small Ball lineup, I think we all know that's a certainty!), then they would own a record that would have tied for or won outright the 4 seed three of the last four years. Minnesota and Memphis got themselves a lot better this year, and you have to take that into account when assessing what the 6 seed really says about the team.

Finally, there is the example of the 95 Rockets that we can all hang our hopes upon. I believe they were a 6 seed that took the whole thing, were they not?

[grndmstr_c]

I'm all for appealing to whatever gods were behind the '95 Rockets' success, but my own take is that HCA does matter. Look at it this way. If home court didn't matter, then we would expect there to be no difference in teams' winning percentages at home vs on the road in the playoffs. However, at least for last year's playoffs, that wasn't the case. The home team won 62.5 % of the playoff games last year. Even when you discount the 4 deciding games that were played on the higher seeded team's home court last year (which introduce a counfound into the analysis - all four were won by the higher seeded, home court team it should be noted), the winning percentage is still 60.7% for the home team. That is to say that the home team, even when the higher and lower seed have an equal number of home games, is still more than 1.5 times more likely to win than the road team based on what happened in the playoffs last year. I should point out, though, that this is averaging across all the pairings, so it still may very well be the case that the value of HCA varies as a function of how closely seeded the teams in question are (as per your post, chumdawg).

[EricaLubarsky]

If we were the best road team in the NBA I wouldnt care.

[OutletPass]

I guess the thing that bothers me most is the "multiple" HCA that a high rated team enjoys. While it's instructive to look in isolation at an individual series, I think it makes more sense to look at the entire playoff progression.

If a #6 seed (such as the Mavs look to be) could beat the HCA three times in a row with regularity, we might be on to something. But failing big upsets by the 7th or 8th seeds, a #6 seed is going to have to win 3 times on the road simply to win the West. And I think that we'll all admit, that doesn't happen at all.

So for me, while the HCA might be overrated in one series, it's underrated when you look at 3 or 4 consecutive series to get you to the West final or the NBA finals. And that's my biggest disappointment about this year...the Mavs have dug themselves a hole the size of Russia...and they'll have to win multiple series ALL ON THE ROAD to get to the top.

If they were a #2 seed or even a #4 seed, there might be some hope for a home series, but at the 6th seed, there's next to no hope at all. All things considered, I'd rather that this team had a home series or two.

I wonder when's the last time that a western team made it to the WCF playing every series on the road
That would be the best indicator to me.

(Good work by Chum and GrandmastC, though....I'm enjoying the renaissance of in depth analytical work on the board that we've been seing in the last month)

[Dirks Cuzin]

Rhylan... ur right that home team is usually the better team... But u dont get how crucial HCA is...


In the regular season... look at the % of HCA winners... still pretty high... it still plays a role

[mavsman55]

The better teams almost always end up winning because:

1. They are a better team naturally (having made it to the top seed)
2. They have HCA (no need to explain)

A top-seed team like L.A. Lakers facing a bottom-seed team like Utah at L.A. would absolutely crush Utah every time. But there is always the chance of an upset, so those stats are a little bit misleading. But as for the Mavs, I can't see them getting out of the 1st or 2nd round max on the road. They simply can't perform up to par when the crowd isn't cheering for them.

To answer the question, HCA matters but only because the teams that have it are probably better than the teams they are facing.

[FilthyFinMavs]

Well I think when it comes to the Mavs if you are at home you think thereis a 75% chance you will win the game. If you are on the road you have to think much lower like in the 40% range. Your chances are better playing at home especially the Mavs who seem to be greatness at home right now. I've seen the Mavs beat some good teams on the road this year and in previous years so you have to think the BIG 3 knows how to deal with it along with Antoine. The rookies and Jamison might have their problems.

[chumdawg]

Originally posted by: OutletPass
I guess the thing that bothers me most is the "multiple" HCA that a high rated team enjoys. While it's instructive to look in isolation at an individual series, I think it makes more sense to look at the entire playoff progression.

Very good point, OP. I agree that this is a much more realistic way of appraising the situation as a whole. In fact, when I looked at the last four years, I believe there was only one team among those nine "road" winners in my analysis that won the next series as well. Actually, it may have been NONE of the teams. However, in most cases the next series those teams played was against an opponent with a much greater won/loss record.

I would imagine the answer to the other point you wondered (last road team to make it to WCF) would be those '95 Rockets. There certainly is precious little precedent.

But then again, I think that we should look at the quality of the eight teams as a whole. Usually you have one or two or three teams that separate themselves from the pack in the regular season. Often the 4 seed will have eight or ten fewer wins than the 1 seed. (And most definitely, the 6 seed usually has that many fewer, if not more.) In these situations, clearly the top few seeds are going to be very difficult to beat.

But this year shakes up a little differently. To this point, there is no clear-cut top team--at least if you look at the records. And the top six teams are separated by only a handful of games. In other words, this year it would be less remarkable if a 6 seed did make it to the WCF. Still remarkable, but maybe not miraculous.

And I still believe that HCA is only a factor if the series goes the distance. If it doesn't, then it is won by the team that wins more road games (loses fewer home games) than the opponent--and both teams have equal opportunities to do so.

[Five-ofan]

For the teams like the mavs and kings hca can actually turn into a disadvantage. They feel that they have to entertain the fans which leads to "van exels" or shots that should have never been taken like a running i handed 3pter with 21 seconds on the shot clock. The crowds get so pumped that the players want to shoot as quickly as possible which to a point is fine if you are good at it(the mavs are) but if it is just a prayer they begin to hurt the team. The lakers vs kings 2 years ago was an example of this. The mavs vs spurs last year is an even better example. The mavs went 2-1 at SA but 0-3 at home. We didn't win a freakin game at home. Just thought I would remind those of you that seem to have forgotten this