Where the heck did the ‘86 Celtics come from? It’s easy to paint them as simply the best team of a dynasty, that the Celtics were really good through the 80s and 1986 happened to be their best year. I don’t buy it. That argument fits more with the ‘85 and ‘87 Lakers. The Lakers were really good very consistently, and they happened to have two stronger years. The jumps up *to* those years weren’t that big, and the drops *from* those years weren’t that big either. But the Celtics? The ‘87 Celtics didn’t even make this list, the ‘84 Celtics were #50, the ‘85 Celtics were team #86 on this list. The best other Bird-era Celtics team here is the ‘81 version, which finished 46th. Contrast those (respectable teams, but nothing earth-shaking) to how freaking dominant the ‘86 Celtics were. 12th best regular season SRS ever, 7th best postseason SRS ever? That’s an insane leap.
To consider how rare a team like the ‘86 Celtics are (considering the seasons before and after them) I want to compare them to other dynasties using my OSRS (which has plenty of flaws, the lord knows, but it’s the best regular season and postseason blended rating I have).
Boston Celtics (‘84 to ‘88):
+7.48 | +7.72 | +12.55 | +5.66 | +5.37
That’s a pretty big jump and fall in the middle there. Check out this next one:
+5.13 | +5.46 | +12.9 | +11.16 | +8.6
That’s Chicago, with the ‘91 season as the +12.9. Massive, massive jump from ‘90 to ‘91 (bigger than the jump for the Celtics from ‘85 to ‘86). And this wasn’t caused by a roster addition; it was just Grant and Pippen (and some others) making the leap at the same time and suddenly giving Jordan a legitimate supporting cast. But unlike the Celtics they maintained around this level for several years. Here’s another:
+7.65 | +11.36 | +8.54 | +11.26 | +6.02
That’s the mid-80s Lakers, with ‘85 and ‘87 as the big seasons. Definitely volatile (jumping 3-4 up or down consistently) but never big swings like the Celtics had. How about:
+2.4 | +8.0 | +12.2 | +9.06 | +3.62
Those are the Shaq Lakers. Big jump from ‘99 to ‘00, but then they got better and maintained kind of for a year before dropping. Definitely more stable than the Celtics. Next:
-0.77 | +8.04 | +11.84 | +8.7 | +3.98
That’s a huge jump between the first two years, but after that it seems fairly slow to change. This is the Kobe Lakers, with the big jump being between ‘07 and ‘08, marked by the addition of Pau Gasol. Another:
-5.07 | +4.58 | +14.68 | +12.34 | +7.09
Check out how big those first two jumps are! These are the Kareem Bucks, starting in 1969. Between ‘69 and ‘70 they added rookie Kareem and Bob Dandridge, and between ‘70 and ‘71 those rookie grew and they added veteran Oscar Robertson. Here’s another:
+4.26 | +12.09 | +10.98 | +16.15 | +12.17
Those are the ‘14-’18 Warriors. That jump in the first year wasn’t adding any new players, it was simply switching to Kerr’s system and everybody staying healthy. And the next big jump was adding Durant. Another:
+9.09 | +10.78 | +12.32 | +6.66 | +12.22
These are the ‘12-’16 Spurs. Those first three years are a steady buildup, 2015 was a weird disappointment and 2016 was outstanding, if spoiled by other super-teams. Another:
+5.04 | +3.72 | +11.77 | +8.86 | -1.02
These are the ‘70-’74 Lakers. The first was a bit low because Wilt missed most of the season, the second was a bit low because West missed the playoffs. Then they explode in ‘72, diminish slightly in ‘73 and in ‘74 Wilt leaves and West plays less than half a season.
Well, I’ll admit, based on all of those samples, maybe the ‘86 Celtics aren’t as much of an aberration as I thought. Here are the top ten jumps from these teams (not exhaustive, just the teams I looked at):
1970 -> 1971 Milwaukee Bucks, +10.1
1969 -> 1970 Milwaukee Bucks, +9.65
2007 -> 2008 Los Angeles Lakers, +8.81
1971 -> 1972 Los Angeles Lakers, +8.05
2014 -> 2015 Golden State Warriors, +7.83
1990 -> 1991 Chicago Bulls, +7.44
1999 -> 2000 Los Angeles Lakers, +5.60
2015 -> 2016 San Antonio Spurs, +5.56
2016 -> 2017 Golden State Warriors, +5.17
1985 -> 1986 Boston Celtics, +4.83
Most of these are driven by player additions (whether that be acquisitions or merely getting players healthy. Of the nine non-Celtics seasons, I’d peg five as being of that sort (Kareem, Oscar, Pau, West being healthy and Durant). Another two are coaching changes (Kerr and Phil Jackson). Player development shows up as a lot of these; the ‘91 Bulls are the biggest example, but the ‘71 Bucks, ‘00 Lakers and ‘16 Spurs all show up. The ‘16 Spurs are a weird example, given that the rating of the ‘15 Spurs is tanked by a first-round exit against strong competition (the Clippers) and Tony Parker being injured for the playoffs.
So where does this leave the ‘86 Celtics? Well, they acquired Bill Walton, so that’s definitely a thing. K.C. Jones was the coach for the whole stretch, so coaching change doesn’t apply. And player development seems unlikely, since their core was all 28 or older except for Danny Ainge (26). But it’s weird to imagine that adding a player that only played 19 minutes a game (Walton) really transformed the team by that much. Let’s look at team drops:
1973 -> 1974 Los Angeles Lakers, -9.88
1986 -> 1987 Boston Celtics, -6.89
2014 -> 2015 San Antonio Spurs, -5.66
2002 -> 2003 Los Angeles Lakers, -5.44
1987 -> 1988 Los Angeles Lakers, -5.24
2011 -> 2012 Los Angeles Lakers, -4.72
2017 -> 2018 Golden State Warriors, -3.98
2010 -> 2011 Los Angeles Lakers, -3.14
2001 -> 2002 Los Angeles Lakers, -3.14
1972 -> 1973 Los Angeles Lakers, -2.91
Note that these drops are almost all smaller than the corresponding jumps. Great teams often get better suddenly, but they get worse more slowly. Some of these are driven by player loss, but many more are driven simply by aging, or a decreased effort. I know that the ‘87 Celtics lost Walton, but I can’t imagine that they gave decreased effort. And their core was all getting older . . . It keeps coming back to Walton. But it’s hard to imagine . . . As a last look, let’s check out the most aberrant seasons, basically seasons that jumped a lot from the year before and then fell the next year:
1971 Milwaukee Bucks, 12.44 swing (+10.1 up, -2.34 down)
1986 Boston Celtics, 11.72 swing (+4.83 up, -6.89 down)
1972 Los Angeles Lakers, 10.96 swing (+8.05 up, -2.91 down)
1991 Chicago Bulls, 9.18 swing (+7.44 up, -1.74 down)
2017 Golden State Warriors, 9.15 swing (+5.17 up, -3.98 down)
2015 Golden State Warriors, 8.94 swing (+7.83 up, -1.11 down)
Many of these are actually big jumps and small falls after a peak year. I think we can actually say that the Celtics’ 1986 season is historically unusual here. You may note that the ‘86 Celtics are the only team to be in the top ten of both rises and subsequent falls. So interesting. Let’s start looking at some possible causes:
Was it the way they used Larry Bird? Bird’s usage dropped in the ‘86 Playoffs, but his efficiency exploded. Maybe other iterations of the Celtics relied on him too much? Let’s check the numbers (from ‘80 to ‘88, regular season to playoff change in usage / true shooting, not opponent adjusted):
1980: -0.1 / -1.8
1981: -1.1 / +1.6
1982: -3.3 / -6.5
1983: +0.8 / -6.1
1984: -0.8 / +6.6
1985: -1.7 / -4.4
1986: -4.3 / +3.7
1987: -1.6 / -2.6
1988: -4.3 / -6.6
The numbers don’t really back this up. If you’re looking for a year that Bird put the team on his back by taking more shots in the playoffs, keep looking. Bird’s usage never jumped by more than a percent, and more often dropped. His only two big jumps in efficiency were ‘84 and ‘86. On average his usage and shooting dropped by almost 2% each (remember, this isn’t opponent adjusted, so dropping by 1.8% shooting is still probably a drop, but smaller than you think). So giving Bird fewer shots doesn’t seem to help too much. So we can cross that off.
Let’s get more granular (different team metrics from ‘84-88, all measured from league average):
Offensive Rating: +3.3 | +4.9 | +4.6 | +5.2 | +7.4
Wow! ‘86 was actually a slightly down year for their offense; it kept getting better in the late 80s.
Offensive eFG%: +0.9% | +1.9% | +2.5% | +4.4% | +5.2%
Yup, definitely driven by shooting. Well, we know that McHale’s peak was around the later years of these five, so that could be part of it. How about passing (Percent of FGM assisted):
Regular Season Passing: 58.6% | 61.5% | 64.2% | 66.4% | 68.0%
Playoff Passing: 55.8% | 62.9% | 65.1% | 63.6% | 70.6%
Wow. That’s very resilient passing; most teams’ A/FGM drops in the postseason, some by a lot (5-6% isn’t crazy). But notice how this keeps going up through the years, as their offensive rating goes up. It’s not crazy that Bird’s passing was improving (cerebral players often improve past their athletic prime) but let’s keep looking . . .
Offensive Rebounding: +1.2% | -0.1% | -1.1% | -4.4% | -3.0%
Huh. The Celtics, despite being an obviously strong rebounding team (when Bird is your 3, you probably should be) they weren’t that good on the offensive glass.
Hey, wait a minute. Increased offensive efficiency, but dropping offensive rebounding, increasing A/FGM . . .
3PA/FGA: 3.2% | 4.2% | 5.4% | 8.0% | 10.2%
Rank in 3PA/FGA: 8th | 6th | 5th | 2nd | 1st
The Celtics’ offense had always shot a fair amount of threes, but by ‘87 it was becoming a major part of their offense. Three pointers are more assisted shots than two pointers, so that explains much of the A/FGM trend, and it also explains much of the drop in offensive rebounding while shooting and offensive efficiency improved. Don’t get it twisted; in ‘88 the league-leading Celtics were shooting only 8.6 threes a game. But it undoubtedly boosted their shooting and spacing more than the rest of the league, which counts. The scary thing about the ‘86 Celtics is that their offense probably could have been even better if they’d moved their playstyle forward several years . . .
That said, this doesn’t address the initial question. Nothing about that trend suggests how the ‘86 Celtics really jumped up in an unsustainable way. If anything, the ‘86 Celtics’ offense was a slightly down year for them; we can’t explain their year that way.
Defensive Efficiency: -3.2 | -1.6 | -4.6 | -1.5 | +1.4
Whoa. Well, pretty sure that’s it. Wait, what happened in ‘84? Well, first off, McHale was coming off the bench and Maxwell was starting. Gerald Henderson was starting and Ainge was coming off the bench. Bird was 27, DJ was 29 and Parish was 30. So the starters were still close to their athletic peaks, Ainge’s minutes were going to a better ball-hawk and McHale . . . I don’t know if him coming off the bench or not helped. In ‘85 all of the core get older, and we lose Maxwell and Henderson. And in ‘86 they get Walton and he magically stays healthy. Sure he’s only playing 19 minutes a night, but he’s the only major change. And the Celtics jump from being a good defense to being the best defense in the league. And is it that crazy? If a healthy Walton can swing a defense by 5 points a game over a season (hypothetical, but not unreasonable) then why can’t Walton swing a defense 3 points a game over a season playing 60% of those minutes? I don’t really see another explanation.
And in ‘87? Walton’s out for the year and their entire bench struggles. Here’s a breakdown of the VORP from each VORP ranked slot (the #1 VORP, etc):
#1: 7.3 | 8.7 | 8.4 | 8.6 | 8.1
#2: 2.8 | 3.0 | 3.9 | 5.5 | 3.3
#3: 2.8 | 2.0 | 2.6 | 2.4 | 3.3
#4: 1.6 | 1.8 | 2.0 | 2.0 | 1.6
#5: 1.5 | 1.8 | 1.8 | 1.2 | 1.4
#6: 1.4 | 0.9 | 1.8 | 0.0 | 0.2
Others: -0.5 | -1.0 | -0.3 | -2.3 | -0.9
1987 was notable for two things: McHale posting an unusually good year and the bench falling apart. The Celtics had always been fairly top-heavy, but after ‘86 their bench was pretty weak. Walton was out, Wedman missed almost the entire year, Parish sprained his ankle and kept playing and McHale broke his foot (hairline, but still).
So, if I’m summarizing, the ‘86 Celtics made the leap by adding Walton (and by him staying healthy), and injuries to pretty much everyone brought the Celtics right back down to merely being very good.
— and that coupled with Hakeem’s increase in games played and slight individual improvement is enough to dethrone him. Impressive three year run though, and I see him as a similarly valid contender for this award until 1990.
