Gabbert’s late-game throws part of offense’s disappearing act

Early in the second quarter Sunday, Blaine Gabbert had a 154.2 passer rating, the 49ers were 6-of-6 on third-down conversions, and they led the Cowboys by two touchdowns. What the heck had gotten into the NFL's 30th-ranked offense and its much-maligned quarterback? After their impressive opening, the 49ers returned to inert mode. Offered left guard Zane Beadles: "Have to really go look at the tape to have many solid answers on what happened." If only the members of the 49ers offense were on the same page in the final three quarters of their third straight loss. Trailing 24-17, the 49ers faced 4th-and-6 at the Cowboys' 35-yard line on the first play after the two-minute warning. Gabbert was flushed out of the pocket to his right and tossed an on-the-run three-yard completion to wide receiver Torrey Smith, who was immediately pushed out of bounds. Kelly said the 49ers (1-3) had three receivers run vertical routes on the fourth-down play, and he thought two were initially held at the line of scrimmage. Gabbert completed 16 of 23 passes for 196 yards with a touchdown and an interception and posted a respectable 91.9 passer rating. [...] Gabbert threw for just 87 yards after the first...