It isn't exactly a surprise that the San Francisco 49ers do not enjoy a lofty position in Pro Football Focus' rankings of every offensive line in the NFL.

Despite boasting the best tackle in football in Trent Williams on the left side of the line, it is an area that has long since been seen as a weakness for the 49ers.

The right side of the line remains a particular area of concern, with it ultimately proving their undoing in their Super Bowl 58 defeat to the Kansas City Chiefs in overtime in February.

PFF ranked the 49ers' top-heavy offensive line 24th in the NFL, with Zoltan Buday writing:

While the 49ers' offensive line features a future Hall of Famer and arguably the best offensive lineman of the past few years in Trent Williams, those around him have so far failed to impress. The rest of the offensive line consists of either career journeymen, such as center Jake Brendel and right guard Jon Feliciano, or young offensive linemen who the 49ers hope can improve in 2024, such as Aaron Banks and Colton McKivitz.

McKivitz was clearly regarded as the weakest link on the O-Line in his first season as a starter in 2023, while the interior has consistently come in for scrutiny. Yet the criticism of Feliciano and especially Banks seems over the top.

Feliciano was PFF's fifth-highest graded guard in the NFL last season and was not credited by the analytics site with giving up a sack. Banks also did not give up a sack and conceded 23 pressures, a long way from the most among guards with at least 200 pass block snaps (Laken Tomlinson – 51). However, Banks' PFF grade put him way down in 60th, below the man he replaced in Tomlinson.

PFF goes into great detail to point out that its grades add context that statistics do not provide, yet its assessment of Banks' performance would appear to suggest that he played at a level reflective of a lineman who should have given up a substantially higher number of pressures.

It's not an entirely implausible argument, given how Brock Purdy's ability to process and deliver the ball quickly can negate missed blocks by offensive linemen, but a look at data from another source does not support it.

Sports Info Solutions has a metric called blown block rate. It defines a 'blown block' as "any time a blocker does not successfully block the defender they attempted to engage with and, as a result, gives the defender an opportunity to negatively affect the play".

Last season, Banks was the sixth-best left guard (min. 200 snaps) in the NFL by blown block rate (1.9%). He was 10th in pass blocking (2.0%) and eighth in run blocking (1.8%).

Add right guards into the mix, and Banks is still 14th among 89 players, ranking 21st in pass blocking and 19th in run blocking.

PFF's grade would point to Banks being one of the worst guards in the NFL. SIS' data points to the opposite being true.

That contrast is illustrative of how difficult it can be to assess offensive line play, but Banks has formed a stellar partnership with Williams and has, over the last two seasons, emerged as a critical player for the 49ers whose blend of size and athletic ability has greatly aided their transition to a run game that now features a greater balance between zone and gap scheme runs.

The 49ers will of course want Banks to continue to develop, and he'll have his sights set on his best season yet in a contract year. However, PFF's critique of a 2023 season in which he fought through some injury issues does look to be very misplaced.

San Francisco 49ers’ 2024 rookie class has chance to be their most impactful since 2019 vintage

It could have a big influence on their fortunes.