How well did the 49ers fare running the ball on first down last year?

Unsurprisingly, running behind Trent Williams led to ample success

For years, it was a predictable start if San Francisco 49ers head coach Kyle Shanahan ran the ball behind left tackle Trent Williams on the first play of every game. However, since Brock Purdy took over under center and with the addition of new talent at the skill position, Shanahan has shown a shift in his play calling on first down, keeping the opposition guessing.

That doesn’t mean he’s ventured away from running the football on first down. The 49ers were among the league leaders in yards per attempt and EPA per attempt on first down runs last year:

It shouldn’t be surprising to see the Niners, Miami Dolphins, and Detroit Lions at the top. Those three and the Rams boasted the best rushing attacks in the NFL.

Those who watched the 49ers play every game understand the dichotomy of success when running in specific directions. These splits will help paint the picture of why the 49ers felt the need to draft an offensive lineman in the third round—which is high for them, considering how offensive line coach Chris Foerster thinks about investing in the trenches compared to skill positions.

When you filter first down runs to a specific side, the 49ers, unsurprisingly, jump to number one in first downs, yards per attempt, and EPA per play when they ran left. Trent Williams is a unicorn. The Niners were among the teams with the lowest “stuff rate” and had the most touchdowns. If No. 71 is involved, good things are inevitable. It only gets better when he teams up with George Kittle.

Conversely, San Francisco found themselves closer to the league average on running plays to the right side, if not worse. The team fell to 21st in overall first downs, 15th in yards per attempt, and dipped to 16th in EPA per play. They had 105 attempts to the right side on first down compared to 125 to the left.

It’s not a shock to see the efficiency dip, but changes are a must when you’re so one-sided. It also might speak to how the 49ers feel about Colton McKivitz and why they might be higher on him than the general public.

The same cannot be said for Spencer Burford or Jon Felciano, which is why they went out and drafted Dominck Puni. Then again, if Chris Hubbard or Brandon Parker beats out McKivitz, the organization is telling us they don’t value— or view it worthy as an investment—right tackle. Hubbard and Parker are journeymen, while McKivitz was a fifth-rounder who rode the bench the first couple of seasons before being inserted into the starting lineup.