Leeds have now started out with the same backline for three league matches running, whereas under previous manager Jesse Marsch there was a tendency to chop and change the defence.
The Whites won with a clean sheet in a Premier League game for the first time since August by defeating relegation rivals Southampton 1-0 over the weekend.
Killgallon thinks it is tough to play when there is not a back four set in stone and stressed that all the great title-winning sides have one.
The ex-Leeds star thinks the Whites suffered because of it earlier in the season but now with more consistency in team-picking, the backline is starting to understand each other a bit more.
Speaking on BBC Radio Leeds post-match, Killgallon said: “For the first bit of the season there was never a set back four, never and it’s tough that.
“You look at all the title-winning title teams, they’ve had the same back four and ‘keeper for virtually the whole way through.
“They’ve all played thirty, forty games including the Champions League.
“You would have [Pascal] Struijk, then you’d have [Diego] Llorente, it was changing all the time.
“Now they are starting to understand, hang on I know [Maximilian] Wober’s going to go in on that side I need to get around here.
“You start picking up little signs of what they do and as a back four today [against Southampton] I thought they looked really solid.”
It was also a member of the defence that scored the goal against Southampton and new Leeds manager Javi Gracia will be hoping that his backline keeps delivering performances like those against the Saints.
