49ers can’t lose again – it’s just math

Here’s a familiar sight from Monday night’s 34-24 loss by the 49ers, a Bills wide receiver (Isaiah McKenzie) running into the end zone. (AP Photo/Ross D. Franklin)Win or go home. It’s that simple after the 49ers 34-24 loss to Buffalo.

Don’t buy it? Check with the coach.

“We’ve got four more games . . . and we’ve got to win all of them,” said Kyle Shanahan.

You know the calculation. The Niners were 5-6 coming into Monday night’s nationally televised game. Ten wins is a perfectly acceptable total for an invitation to the playoffs. To get to 10-6, San Francisco had to beat Buffalo and win the next four.

However, there were some optimists who said the team could lose one of the last five and still…