Watford boss Javi Gracia says he believes different formations are "only numbers" as he begins his second spell in charge of the team.
The Spaniard returned to the club earlier this month to replace Paulo Pezzolano, who was sacked after just 10 games in charge.
Gracia will be in the dugout at Sheffield United on Saturday with the Hornets 11th in the table - but only three points adrift of the play-off places.
He has preferred to use a back four in the past but Gracia told BBC Three Counties Radio: "Today the shapes are changing - 3-2-5, 3-1-6 - now for me that is not so important, they are only numbers.