Kurtenbach: The 49ers just beat up two of the NFL’s top lines. That’s a big deal entering winter football season

When the weather turns nasty, the NFL becomes nastier.

Leave that “basketball on turf” nonsense for the sunshine. When it’s cold, and the games really matter, they’re won or lost in the trenches by the big uglies on the offensive line and defensive line.

It warms my heart.

If you’re a 49ers fan, watching the performance of San Francisco’s offensive and defensive lines in Sunday’s win over the Eagles likely warmed your heart, too.

Both units were outstanding. And that should set a tone for the rest of the season...