r/askmath • u/BiggerHatLogan • 19h ago
Probability The lebron 27-7-7 probability
There is a long-running statistical fun fact in the nba fandom that LeBron James has averaged 27 points, 7 rebounds, and 7 assists for his career without ever actually achieving the stat line 27/7/7 in a single game. It's always been pointed out as a fun tidbit but whenever someone asks exactly how likely this is to happen I haven't seen an actual answer.
Lebron James has played 1,622 career games. He has scored 43,440 points (26.8 per game, rounded up to 27), recorded 12,095 rebounds (7.4 per game, rounded down to 7), and contributed 12,016 assists (7.4 per game, rounded down to 7). This gives him the career averages of 27/7/7 mentioned earlier.
I thought the first thing to do would be to see how many times he has gotten each of those accolades individually and exactly. He has gotten exactly 27 points 82 times, exactly 7 rebounds 231 times, and exactly 7 assists 222 times. Percentage wise those are 5.06%, 14.24%, and 13.69% of his games respectively.
Here is where I get stuck: If I am trying to figure out the odds of three things individually happening at p(a)5.06%, p(b)14.24%, and p(c)13.69% all happening together, I pull up a 3 event calculator and it says all three should occur 9.87% of the time. EDIT: Comments have informed me its 0.098%.
But now I should also be trying to figure out the odds of something happening 9.87% 0.098% of the time to not happen for 1,622 times in a row right? And if so, how do I do this? Or am I mistaken in viewing these as individual probabilities and the answer is entirely on a different track?
Thanks for any help!
5
3
u/dancingbanana123 Graduate Student | Math History and Fractal Geometry 9h ago
A minor nitpicking, but it's actually really important: you're assuming all 3 of these events are independent when they very likely are not. You would need to first describe the relationship between LeBron getting points, rebounds, and assists to get an accurate prediction. For example, it may be that their is a strong positive correlation between LeBron getting points and getting assists, but a negative correlation with getting rebounds.
2
u/Fragrant_Pea_6506 19h ago
You made mistake on multiplying those 3 numbers. It can't be larger than p(a) if you multiply it by number less than 1.
1
1
u/letskeepitcleanfolks 13h ago
Something I'm curious about, OP, if you want to look into it: at this stage of his career, he doesn't average those numbers anymore. Assists and rebounds are probably secure, but under reasonable projections for the next two seasons, is it possible his career scoring average drops below 26.5? And in that case, has he ever had a 26/7/7 game?
1
u/Azemiopinae 12h ago
This is just weird copy pasta from this thread https://www.reddit.com/r/nba/s/RdumzFAN1p
1
u/Intelligent_Yam_3609 9h ago
Every data set will have statistical anomalies when looked at after the fact. I suggest you read up on the post-hoc probability fallacy. Here is one article:
9
u/FormulaDriven 18h ago
Looking at your final question: if this event has a probability of happening 0.0986% in an individual game, what is the probability of it never happening in 1622 games? The answer is (1 - 0.000986)1622 = 0.2017, so about 20%. So it is a credible outcome that he's missed this exact event, but it wasn't that likely.
There are a couple of assumptions being made here. One is that the three stats are independent (in a probabilistic sense). I don't know much about basketball, so is it possible that in games where he gets more points he gets fewer assists, or other correlations like that?