Super Bowl Features Two Second-Half Titans

The Chiefs have the best second-half defense in football and face a 49ers team in Super Bowl LVIII that led the NFL in second-half points.

These trends have accelerated in the postseason, with the Chiefs allowing just 3.3 points per game in the second half and the 49ers scoring 22 per game after halftime.

This compares with the 6.8 Kansas City allowed to opponents in the second half during the regular season and the 14.1 scored by San Francisco.

That Kansas City points allowed for the regular season is the best since 2020. The Niners second-half scoring is the most since 2021.

The Chiefs 3.3 allowed is the fewest of any undefeated team in the postseason since 2017 and the record for a team that won the Super Bowl in that period is the seven points allowed per game in the second half by the 2017 Eagles (two shutouts and then 21 points to the Patriots).

The Niners’ 22 points per game in the second half is the most since 2017 of any team that played multiple postseason games.

Teams A Combined 31-5-3 To Second-Half Under

Note the O/U in the second half of this game is 24 points.

The Chiefs are 19-1 to the under in their games this year. The Niners in their games are 12-4-3 in going Under 24 points in the second half. That’s a combined 31-5-3.

The one game where the Chiefs went over that total was in Green Bay on December 3, when the two teams combined for 26 points in a 27-19 Kansas City loss.

Green Bay had scoring drives of 67, 55, and 35 yards in the second half of that game.

The Packers averaged 4.9 yards rushing in the second half.

What makes these teams so good in the second half?

There’s some luck involved. Measured by Expected Points Added, the Chiefs are the fifth-best second-half defense, well behind the league-leading Jets.

he Niners measured the same way trail only the Bills, who the Chiefs have already thwarted in the second half (as for KC’s other postseason opponents, the Ravens ranked ninth and the Dolphins 11th).

The Chiefs’ defense is seventh in blitz rate, seventh in pressure rate, and fifth in sack rate in the second half. In the first half, they’re 14th in blitz rate, fifth in pressure rate, and first in sack rate.

So they blitz more but not a crazy amount more.

They play two high in the second half twice as often as one high, the opposite of most teams, conceding the run to limit big plays.

They’re more conservative in their coverage in the first half than in the second, though they play one high the lowest percentage of plays in the first half, too.

Safety First For Chiefs

What’s unusual about the Chiefs is their mixture of safer two-high coverages and blitzing.

Again, they’re seventh in second-half blitz rate.

The other teams in the top 10 play one high safety an average of 56.2% of the time to complement that blitzing.

The Chiefs only do it 34.9% (the average for all teams is 52.8%).

In the postseason, the Chiefs are playing a lot more zone in the second half (71.3% compared with 63% in the regular season).

They’re also blitzing a lot less (24.7% vs. 30.7%, the regular season average was 25.5%).

So they appear to be crossing teams up.

Their pressure rate is actually below the postseason average of 37.1% and less than their second-half regular-season average (34.1% vs. 40.1%).

So they’re winning more with coverage than with pressure.

Niners Run Even vs. Stacked Boxes

The 49ers aren’t doing anything great in the second half in the passing game this postseason.

Brock Purdy has been fine.

But their running game has been phenomenal, with 0.30 EPA per rush despite seeing eight men in the box more than half the time, which is incredible given that the Niners have been trailing for most of the second halves.

In other words, the defense is daring the Niners to throw despite the Niners trailing and the Niners are refusing to throw anyway.

They do not want Brock Purdy to be the focal point of this offense.

The second half of the Super Bowl will be fascinating.

The Chiefs want to play two high, have six or fewer defenders in the box on most plays (50% even on first down), and dare you to run.

The Niners, no matter how desperate the score seems, want to remain balanced and still lean heavily into the running game, refusing to pass aggressively.

The Chiefs thus far in the postseason have played the style of defense that the 49ers would seem to prefer.

However, you would have said the same thing about the Ravens who, for some reason, refused to run in a close game in the second half.

It would be shocking if the Niners followed suit.

But Kansas City defensive coordinator Steve Spagnuola is very adaptable and could change things up in the second half on Sunday by daring Brock Purdy to beat him.