Blake Shelton Scores 15th Country Airplay No. 1

Blake Shelton performs during the Healing in the Heartland: Relief Benefit Concert on May 29, 2013 in Oklahoma City, Oklahoma.

NBC via Getty Images

The coach on NBC's 'The Voice' narrowly bests Tim McGraw for the radio ranking's new leader

In one of the tightest No. 1 battles since Billboard's Country Airplay chart switched from a plays-based to an audience impressions-based methodology almost nine years ago, Blake Shelton's "Mine Would Be You" (4-1) becomes his 15th leader by a margin of just 18,500 audience impressions, according to Nielsen BDS, edging Tim McGraw's "Southern Girl" (3-2).

Since the chart's formula changed in January 2005, the margin separating the top two songs has been closer five times, the snuggest being a tie between Sugarland's "Settlin' " (2-1) and Rascal Flatts' "Stand" (1-2) on the May 19, 2007, chart; ties are broken by placing the title with the largest increase first. Shelton's chart-topping finish is the closest since Taylor Swift's "You Belong with Me" (3-1) surpassed Darius Rucker's "Alright" (1-2) by just 200 impressions (Aug. 22, 2009).

"Mine" marks the third straight leader from Shelton's album "Based on a True Story…," after "Boys 'Round Here," which topped the June 29 chart, and "Sure Be Cool If You Did," which spent two weeks at No. 1 in March/April. Since his first week at the summit (Aug. 11, 2001), Shelton is tied with Toby Keith for the third-most No. 1s, trailing only Kenny Chesney (18) and Brad Paisley (16).

Since Country Airplay launched in 1990, Shelton and Keith Urban are tied for ninth place among acts with the most No. 1s. Alan Jackson, George Strait and McGraw lead (26 apiece), followed by Chesney (22), Brooks & Dunn, Keith (20 each), and Paisley and Garth Brooks (18 each).

Here's a look at Shelton's 15 Country Airplay No. 1s. Perhaps unsurprisingly, he's tallied almost half (seven) of his leaders since becoming a coach on NBC's "The Voice," which premiered April 26, 2011:

2001, "Austin"
2003, "The Baby"
2004, "Some Beach"
2008, "Home"
2009, "She Wouldn't Be Gone"
2010, "Hillbilly Bone" (featuring Trace Adkins)
2010, "All About Tonight"
2011, "Who Are You When I'm Not Looking"
2011, "Honey Bee"
2011, "God Gave Me You"
2012, "Drink On It"
2012, "Over"
2013, "Sure Be Cool If You Did"
2013, "Boys 'Round Here" (featuring Pistol Annies & Friends)
2013, "Mine Would Be You"