While Dave Henigan’s Grapevine football team is still searching for its first win of 2013, he keeps pointing to the most important elements where encouragement can be found.In four of Grapevine’s first five games, the Mustangs have pretty much been in them through the first half. They’ve kept it within one or two scores. The problem comes in the second half, where the mistakes begin and games get away from the Mustangs (0-5, 0-2 in District 6-5A).Look no further than last Friday’s 41-7 loss to Colleyville Heritage. Grapevine trailed 20-7, at halftime and had the ball to start the second half. But quarterback Sam Barry lost his helmet on the second play and had to come out of the ballgame. Replacement Adam Sandy came in, threw an interception and the Panthers capitalized to extend the lead. From there, Colleyville Heritage scored twice more in the period to win comfortably.“It’s turnovers,” Henigan said. “When we turn it over in our end of the field, it just puts us in a difficult spot. When you give people a short field, your defense is going to break.”When the Mustangs play at Irving (3-2, 1-1) on Friday at Irving Schools Stadium, they will enter the game with 15 turnovers (11 interceptions, four lost fumbles) in their first five games. Henigan knows that the lack of depth forces his team to play perfect.“They don’t like it. No one likes it,” Henigan said. “But their attitude has been great. And really, the Tuesday and Wednesday practices before the Colleyville Heritage game were the best ones we’ve had all season.”Irving, though, makes teams prepare for a little bit of everything. When Henigan and his staff broke down the Tigers, they counted 27 different formations. A tale of two seasonsLook at the first half of Grapevine’s season and followers will tell you the Mustangs wound up playing one of the toughest schedules in the Dallas-Fort Worth area.Between Keller Fossil Ridge (4-1), Justin Northwest (4-1), Sachse (6-0), Hurst L.D. Bell (4-1) and Colleyville Heritage (3-2), those teams are a combined 21-5. The second half of the season is comprised of Irving (3-2), Euless Trinity (3-2), Irving MacArthur (2-3), Carrollton R.L. Turner (0-5) and Irving Nimitz (2-3). Those teams are a combined 10-15. Of course, Trinity is still Trinity, and it hasn’t lost a district game in about 10 years.“We’re at halftime of our season,” Henigan said. “As far as district goes, we are midway through second quarter. There are two choices. We either quit or we keep fighting. As coaches, there is only one option and that’s to fight. Our kids will do that.”• Irving MacArthur (2-3, 1-1) at Colleyville Heritage (3-2, 1-1)7:30 p.m. Friday Mustang-Panther Stadium, Grapevine The skinny: The Panthers got good news last week when senior quarterback Griffin Pickler was cleared to play against Grapevine after suffering an apparent head injury. While the offense still had its struggles, the Panthers pulled away. The defense must be ready for an explosive MacArthur team. Quarterback Logan Austin has already thrown for 1,026 yards and six scores. Colleyville Heritage has won the first three district meetings going back to 2010.