SAN FRANCISCO — To call Landen Roupp headstrong would be an understatement.There are times on the mound when he conjures Madison Bumgarner, swiping a cleat against the slab and glaring at an opposing hitter whose very presence in the box seems a personal affront. There are times when he conjures Ryan Vogelsong, refusing to yield even if it means grinding through one 3-2 count after another and treating every open base as if he’s a nervous talk show audience coordinator with seats to fill.There have been times when Roupp’s competitiveness and stuff have allowed the San Francisco Giants to dream on those Bumgarner/Vogelsong comparisons. He spins one of the league’s better curveballs. His two-seam fastball and changeup have the potential to be plus pitches. The cutter is finding its place. Lord knows he has the intangibles. Who knows? He might even insist on eating chicken enchiladas the night before a start.Among the assemblage of arms on the Giants’ 40-man roster hoping to establish themselves in the big leagues this season, an ambition that has gone largely unrealized under the franchise’s third wave of pitching coaches in four years, Roupp, a 27-year-old right-hander, stood out as the likeliest to claim a lasting place in a major-league rotation.But there’s a difference between taking the ball every fifth day and establishing yourself as a major-league starting pitcher. Roupp had done more of the former than the latter this season. When he took the mound Monday night in a homestand opener against the Toronto Blue Jays, he was seeking his first victory since April 26. The Giants had lost 11 consecutive games with him on the mound. It was the longest stretch without a team win for a Giants starting pitcher since left-hander Pat Misch in 2007-08.It’s an entirely separate matter, but the attention Roupp got after he wrote a bible verse on his Pride Night hat on June 12 probably did him no favors, putting himself and three teammates in the center of a culture war that struck nerves, revealed organizational disarray and had no shortage of co-opters and grandstanders.Purely from a pitching standpoint, though, Roupp’s promising April unraveled for two reasons.The first reason was inefficiency. He has the stuff to churn quick outs through contact — his 49.8 percent ground-ball rate is just a shade below Logan Webb’s elite 51.6 percent — but hadn’t been utilizing it to his advantage. Instead, Roupp entered Monday averaging 18.3 pitches per inning, which was the second most among pitchers who had thrown at least 85 innings this season. His 4.28 pitches per plate appearance also ranked as the second highest among qualified major-league starting pitchers.The second reason was that his sinking, two-seam fastball was getting pounded. Opponents hit .114 against the pitch in his first six starts. They hit .365 with 13 extra-base hits (four home runs) against the sinker in 11 starts after that.“The last couple months, I was pretty slow with my front side, so just speeding that up a little bit and really just wanting to compete,” Roupp said. “I knew I needed to be better for the team. I haven’t been great, shoot, the last six or seven outings. So it was a really good feeling to go out there and compete and give the team a chance to win.”