Why isn’t the 49ers’ record better entering showdown with Packers?

The San Francisco 49ers will enter Sunday’s showdown with the Green Bay Packers ranked fourth in the NFL in overall grade at Pro Football Focus, sixth in DVOA, third in adjusted net yards/passing attempt, fifth in expected points added per play and second in yards gained per play.

But Kyle Shanahan’s team is also 5-5 and haven’t won back-to-back games all season, making Sunday’s visit to Lambeau Field something close to a must-win game if the 49ers are going to stay in the race in the NFC playoffs.

So, what gives?

Kyle Madson, the managing editor of Niners Wire, helped us answer the question.

“The bottom line with the 49ers is that their top-heavy roster is coming back to bite them. I could…