The left half of the Left Arrow hosts three intertwined routes. There are two starts, one middle, and two finishes, which any math geek can tell you results in four possible pertubations, however, only 3 currently "exist" as named routes. Feel free to do the fourth as well.
TIR is the easiest to describe, as it simply starts on, stays on, and finishes on the furthest left line of bolts. The route begins on the approach trail, which is a bit of a hassle for the belayer and leader for rope management. Good climb on excellent rock.
Furthest left route on the Left Arrow.
8 or 9 bolts to a 2-bolt anchor, depending how close you want them when the climbs join/split one another. Stick Clip recommended.