There’s a reason sing-songy choruses have gone from frowned upon to practically mandatory. At press time, 16 out of 21 rap singles on the Billboard Hot 100 featured singing hooks. Black Eyed Peas' "Boom Boom Pow" and "Imma Be" are the only No.1 rap singles out of 15 chart toppers that didn't feature singing in the past three years. Needless to say, the singing hook formula has proven to be a successful.

Though he’s considerably slowed down in the past two years, T-Pain, who has made a career out of guesting on rap singles, is presently featured on two songs on the Hot 100: Pitbull’s “Baby,” which peaked at No.7 a few weeks back and DJ Khaled’s “Welcome to My Hood,” which now ranks at No. 79. Meanwhile, Skylar Grey appears to be picking up steam. The singer/songwriter, who penned Rihanna’s chorus on Eminem’s No.1 single, “Love the Way You Lie,” is presently featured on Dr. Dre’s “I Need a Doctor,” which peaked at No.4 and Diddy-Dirty Money’s “Coming Home,” which peaked at No.11. The late great Nate Dogg, Akon and Pharrell Williams,  just to name a few, have all taken turns as hip-hop’s hookman du jour. Even rappers-turned-part-time-singers like 50 Cent, Lil Wayne and Drake have become sought after hookmen, but who exactly provides more bang for your buck? Which hook man is the most efficient?

XXL takes a look at 25 in-demand hook specialists and finds out who has the best batting average.— XXL Staff

[Editor's Note: A song has to chart in the Top 40 of the Billboard Hot 100 to be considered a hit. The slugging percentage is the ratio of Top 10 singles.]