Following back to back wins over division rivals, the Colts' returned to Lucas Oil Stadium to face the Baltimore Ravens. Andrew Luck and the Colts' offense drove 59 yards on their first offensive possession, with the drive ending on a turnover after the Colts failed to convert a fourth down. On the first play of the Ravens' offensive possession, Steve Smith fumbled the ball, which was then recovered by Montori Hughes of the Colts. The Colts settled for a 38-yard field goal by Adam Vinatieri, giving then an early 3-0 lead. A muffed punt return by Jacoby Jones resulted in a second Ravens' turnover, however, on the ensuing Colts' drive, Haloti Ngata intercepted Luck, their first turnover of the game. After a stalled Ravens' drive early in the second quarter, the Colts drove 70-yards in 20 plays, though they again settled for a Vinatieri. The Ravens responded, scoring on a 52-yard field goal from Justin Tucker as time expired, cutting the Colts' lead to 6-3 at halftime. The Ravens opened the second half on offense and committed their third turnover on a Joe Flacco interception by Vontae Davis. The Colts' took advantage of the turnover, by scoring their first touchdown on a Luck touchdown pass from Dwayne Allen, giving them a 13-3 lead. The Ravens' defense again stepped up later in the third quarter, forcing the Colts' second turnover on a Luck interception by C.J. Mosley, which resulted in a second Tucker field goal. The Colts again extended their lead early in the fourth quarter on a Luck touchdown run, which gave the Colts a two possession lead at 20-6. The Ravens closed the gap again on their ensuing possession, Justin Forsett 11-yard touchdown run, cutting the lead back to one possession. After driving down to the Ravens' 10-yard line, Colts running back Ahmad Bradshaw fumbled the ball, giving the Ravens possession with under two minutes remaining in the game. The Colts' defense forced a turnover on downs and sealed the 20-13 win. With the win, the Colts improved to 3-2.
Question: How many more touchdowns were there in the second half than the first half?
Answer: 4