In light of last week's announcement that the Grammys will henceforth have eight nominees in each of their marquee categories, I have two words of advice for the Nominations Review Committee: Tread carefully.

They may be tempted to flood the zone with hip and progressive choices, but that may only serve to enable another victory by a safe, conventional choice. It has been known to happen.

Just last year, the Nominations Review Committee nominated two rap albums (Kendrick Lamar's DAMN. and Jay-Z's 4:44) and an urban contemporary album (Childish Gambino's "Awaken, My Love!") and then watched as Bruno Mars' 24K Magic snatched the trophy. Lamar might have been able to beat Mars in a one-on-one contest, but when the committee threw a second rap icon into the mix, and an urban contemporary star to boot, they unwittingly made Lamar's path to victory much harder.

Here are seven other cases where artists who appealed to the same basic voting bloc or blocs appeared to split the vote in the Album of the Year category.

2014—Beyoncé's Beyoncé and Pharrell Williams' GIRL divided the urban contemporary vote, while Sam Smith's In the Lonely Hour and Ed Sheeran's X split the pop vote. The fifth nominee, Beck's Morning Phase, had the rock vote all to itself and won.

2004—The nominees included three highly contemporary R&B or rap albums (Usher's Confessions, Alicia Keys' The Diary of Alicia Keys and Kanye West's The College Dropout). With that vote so divided, the award went to Ray Charles' Genius Loves Company, a posthumously-released collection of duets.

1991—Three albums (R.E.M.'s Out of Time, Paul Simon's The Rhythm of the Saints and Bonnie Raitt's Luck of the Draw) split the contemporary pop/rock vote, allowing Natalie Cole to take the prize with Unforgettable with Love, a nostalgic valentine to her late father, Nat "King" Cole.

1987—U2's rock classic The Joshua Tree was a widely hailed choice, but let the record show, its path to victory was made easier by the fact that three albums—Prince's Sign o' the Times, Michael Jackson's Bad and Whitney Houston's Whitney—split the pop/R&B vote.

1984—Two rock classics—Bruce Springsteen's Born in the U.S.A. and Prince and the Revolution's Purple Rain soundtrack—were assumed to be the front-runners. One album or the other held the No. 1 spot for 31 consecutive weeks. If just one of these albums had been nominated, it might well have won, but there weren't enough rock-leaning voters in the academy at the time for a rock album to win when the rock vote was split right down the middle. Lionel Richie's less heralded (though still enormously successful) Can't Slow Down took the lion's share of the pop vote and won the award.

The Nominations Review Committee may be tempted to flood the zone with hip and progressive choices, but that may only serve to enable another victory by a safe, conventional choice. It has been known to happen.

1974—Two classic pop/rock albums (Joni Mitchell's Court and Spark and Paul McCartney & Wings' Band on the Run) and a third that isn't quite as revered today (Elton John's Caribou) were nominated. With the pop/rock vote split three ways, Stevie Wonder was able to win (for the second year in a row) with Fulfillingness' First Finale, even though it isn't generally considered the equal of his two previous albums (Talking Book and Innervisions) or his next album (Songs in the Key of Life).

1958—Two Frank Sinatra albums (Come Fly with Me and Frank Sinatra Sings for Only the Lonely) were nominated in this, the Grammys' first year. Even Ol' Blue Eyes, at the peak of his powers, couldn't win when his votes were split in two. Henry Mancini's jazz-oriented TV soundtrack, The Music from Peter Gunn, took the award. (Sinatra came back to win the following year. And the rules were changed so an artist wouldn't be forced to compete against himself.)