Six games remain in the 49ers’ season, ample time remains for players to make an impression before more roster turnover strikes next year. Here is a bye-week look at how each position shapes up for 2018 in three separate categories: * * * Quarterback Best bets: Jimmy Garoppolo, C.J. Beathard Not sure/Doubtful: N/A Analysis: By winning his last start in impressive and cohesive fashion, Beathard could further delay Garoppolo’s debut. Garoppolo does not need to audition for 2018, as the brass is convinced he can be their franchise quarterback for years to come, even if a franchise tag is needed to retain him in 2018 if no multi-year deal is reached. * * * Running back Best bets: Matt Breida. Not sure: Carlos Hyde, Joe Williams (IR), Raheem Mostert Doubtful: N/A Analysis: Hyde will have a nice pay day if he avoids serious injury the final six games, but who’s paying? The 49ers have yet to strike an extension, and he could find a better suitor or playoff-ready team in free agency. Breida has shown spark as a rookie backup but must improve on his league-low average of 1.15 yards-after-contact, per ESPN’s stats. Williams, a fourth-round pick, went on IR before his rookie season and better look, um, better in 2018. Mostert has had mixed production on special teams.