It is a debate that is growing around Villa Park and one that Lawrie Sanchez, the Northern Ireland head coach, inadvertently entered.
Stiliyan Petrov or Steven Davis?
Everybody, it seems, has their opinion, but only one man — Martin O'Neill — has the answer. Based on the past four matches, which have spanned nearly two months, the answer is emphatically Petrov.
Petrov and Davis have been part of the same Villa midfield this season but perceptions remain that only one of them can occupy a slot in O'Neill's 4-3-2-1 formation at any one time.
That has been bad news for Davis because, while he has tasted action in 27 matches for Villa this season, and is usually in the 16-man squad, he has been more peripheral than he was last season.
Sanchez is surprised. Davis produced two superlative performances for Northern Ireland last week — against Liechtenstein and Sweden — and only missed out on man-of-the-match awards because of the scoring form of David Healy.
"Aston Villa must have some team if Steven Davis cannot get into it," Sanchez said.
It was a colourful way to pay Davis a compliment and it gives credence to the view of those who cannot understand why the midfield player has not consolidated his first-team place.
Petrov, by contrast, has taken time to settle in the first team and has yet to match his performance, last September, on his debut against West Ham United.
One can understand O'Neill's desire to persevere with Petrov. The manager knows more about the Bulgarian than anyone else in the game and knows that the player will come good. After all, Petrov took time to settle as a player with Celtic but still flourished into a classy midfield player.
O'Neill is not even attempting to conceal the view that Petrov has fallen short of expectations. But patience is a virtue to O'Neill and there are no suggestions that Petrov will be dropped.
"Petrov has got much more to offer than he has shown for the bulk of this season," O'Neill said. "I am not saying he could not perform every single week like he did on his debut against West Ham United but he could certainly aspire to those heights for a more consistent basis.
"I think the whole season has been a major learning part for him. He now knows what the Premiership is all about and you will see a different Petrov from now on in.
"I would have expected him to score more goals, play stronger and have a greater influence in games. I have a belief that will come and I have never wavered from that belief.
"It took him a while at Celtic to settle in but he was then only 19. Here he is a mature young man and he should be able to adjust to the changes of environment and change of life."
Petrov has played 28 matches for Villa and has scored just one goal. Davies was more prolific last season but, unlike Petrov, had the advantage of a background steeped in the procedures of Villa.
Not since January 2, when Villa played Chelsea, have Petrov and Davis started a match together. They proved that night that they can complement each other. With Gavin McCann suspended for two matches from next week, Petrov and Davis may yet gain the chance to work together again.
Whatever, O'Neill is aware of what Davis did in the Villa team last season and regards his fellow Ulsterman as an integral part of the first-team squad. The facts back him up. How often is Davis missing from the 16-man squad?
"[The match against Liverpool on March 18] was the first time he has been out of the 16 all season," O'Neill told Villa's official website two weeks ago. "It is his second full season after having done so well before and he is not the first young player to struggle to find his feet after an impressive start.
"With the balance of trying to win some games with young players coming into the side and trying to gradually improve your lot — a lot of the things that are happening are to be expected.
"We were going into games around the Christmas period where the bulk of the side was made up from lads from the academy. That is asking a lot of players like Steven Davis."
But, as Sanchez implies, it says a lot about Villa that they can afford to put a player on Davis's ability on the substitutes' bench. Somewhere in there, too, is a compliment to Petrov.