Chiefs December Home vs Away

Fido. We go home.The Chiefs have an extreme differential in winning percentage at home vs non playoff teams as opposed to away playoff teams during December. Obviously, you would expect a team to lose on the road against an opponent good enough to make the post-season. And, of course, you expect the opposite when playing a weak team at home. But, even though we can all agree on that premise, the December numbers are truly amazing.

The fact is that since 1991, Kansas City is 0-12 against playoff teams on the road. The flip side is that during the same period of time, they are 20-1 (16 straight) against non-playoff teams at home (losing only to Denver in 1994). One wonders if there is a valid reason for why it is so extreme. The answer is, “I don’t know.”

However, what I do know is this. The same pattern is nowhere near as clear for September, October or November. Here is a table showing each month and the two situations under discussion – playoff teams on the road and non-playoff teams at home.

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As you can clearly see, December appears to be in a different category than the rest of the months in both cases. It could be coincidence, but it could also be something related to the colder weather. What I don’t know for sure is whether this tendency is true for other teams in December. Perhaps, but I doubt it.

Common sense says previous December trends could be thrown out the window when looking at the upcoming games – starting with tomorrow's road playoff game (Denver). However, these trends are strong enough that I might consider factoring in a couple points to the line if I were betting on the games.

This is probably a good time to question whether statistical anomalies such as this example have any validity. As always, the first issue is sample size. If the Royals have won every single time in their history in the second game of a Tuesday double header in the month of July, does that mean the next time it happens, they are more likely to win? Of course not because 1) it’s probably only happened a few times (small sample size) and 2) nobody associated with it has any awareness of the event and thus, it cannot be affected by cause.

Another example. If there is a 50-50 chance of something happening and it happens 10 times in a row, does that make it a trend? If it’s flipping a coin, obviously not. You will get either heads or tails 10 consecutive times every 512 attempts. That’s not exactly rare – just coincidence. And (hopefully, I didn’t need to say this), if a coin is heads 10 consecutive times, the odds of a heads on the 11^th flip are still 50-50.

When people argue X is more likely to happen whenever Y and Z converge… when Y and Z have nothing to do with each other, I just want to scream. The two common examples are the Stock Market/Super Bowl and the Presidential Election/Washington Redskins. I’ll go into those at some other time. The point is “correlation” without “causation” equals “coincidence”. No exceptions.

Therefore, unless someone can come up with a reason (cause) for why the December phenomena would be true for the Chiefs, it’s purely luck IMO. Nevertheless, it is still fun to identify and comment on streaks of this nature. I’m a very streak-oriented person and I enjoy discovering them, but, I fully recognize millions of streaks can be found if you make your parameters broad enough.

So, I cannot say the Chiefs will lose at Denver because they have lost the last 12 road games to a playoff team in December. And, I can’t say that if the Chiefs win, it means Denver won’t make the playoffs. But, I can say that the streak is pretty solid and the odds are clearly in favor of Denver making it 13-0.

The next game is San Diego (unlikely to make the playoffs). The Chiefs play them at home. So, if form holds, KC will win that game and go 22-1 against non-playoff teams at home in December.

The Miami game is at home and would only be relevant if they don’t make the playoffs – which we don’t know yet. Finally, Cincy is on the road and they are not going anywhere in the post-season.

I’ll come back to this discussion later in the month and see how it worked out.