Here’s more proof to show “base defense” doesn’t matter

When James Bettcher became the defensive coordinator of the New York Giants, there was a lot of talk about a switch between a 4-3 defense and Bettcher’s prefered 3-4 base. The problem with concerns over the base defense is there’s been a shifting definition of what a base defense is in the modern NFL.

Per Football Outsiders, just three teams played a “base” defense at least half the time in 2017. The other teams prefered nickel (five defensive backs) and dime (six). League-wide, 52.3 percent of defensive plays came in nickel last season and an additional 12.9 percent came with more than five defensive backs on the field.

Bettcher’s Arizona Cardinals were one of the teams that took advantage of those extra defensive backs. The Cardinals used nicked 65 percent of the time, which was the seventh-highest rate in the league last season. Arizona only used “base” personnel on 27 percent of its defensive plays, which ranked 24th among teams. Last season, the Giants were in “base” on 29 percent of defensive snaps (21st) and in nickel 60 percent of the time (15th).

When it comes to nickel, there’s also different ways to play with five defensive backs. Arizona’s most common lineup last season was a 2-4-5 with two defensive linemen (Frostee Rucker and Corey Peters), four linebackers (Haason Reddick, Karlos Dansby, Markus Golden, and Chandler Jones), and five defensive backs (Patrick Peterson, Justin Bethel, Tyvon Branch, Antoine Bethea, and Tyrann Mathieu). That lineup played together on 54 of Arizona’s 1008 defensive snaps (5.36 percent). Even at just over five percent, only six teams had a most-common lineup played more often.

Meanwhile Arizona’s best defensive lineup by yards per play used on 15 or more snaps had a 3-3-5 look with Olsen Pierre, Josh Mauro, and Frostee Rucker on the line, Bucannon, Jones, and Dansby at linebacker, and a secondary of Peterson, Bethea, Mathieu, Tramon WIlliams, and Budda Baker. That grouping allowed just 1.47 yards per play on a small sample of just 17 plays, tied for the fifth-most common lineup for Bettcher’s defense.

The Cardinals also had 15 unique starting lineups on defense across the 16 game season — only the Giants and Tampa Bay Buccaneers had more. But while the Giants and Bucs dealt with injuries and ineffectiveness, the Cardinals defense used its versatility to be one of the league’s top defenses. Arizona ranked fifth in defensive DVOA and tied for the third fewest yards per play allowed.

It remains to be seen if the current personnel for the Giants defense has enough versatility to mix and match the way Bettcher has done in the past. We also don’t yet know if the depth in the secondary is good enough for the Giants to continually run out nickel and dime packages over 70 percent of the time. But what this does show is we shouldn’t get too caught up in labels like “base defense” or really who the defensive starters will be. There’s going to be a lot of movement on this defense, in terms of positional personnel and the players on the field. Bettcher’s defense is going to be a new look for the Giants and the looks will continually evolve over the course of the season.