The Black Cats have scored two goals from corners in their last two league games, following Jimmy Dunne's header at Oxford and Jack Baldwin's goal against Blackpool.
Ross insists it's something they've been working on throughout the campaign, even if it's only just come to fruition, with January signing Grant Leadbitter providing two assists in two games from corners.
"That's testament to the diligence of the staff and the players," said Ross following the 1-1 draw with Blackpool.
"Just because we've scored two goals in the last two games from set-pieces it's not just because we've done them this week, we've been working hard on them for a long,long time.
Sunderland AFC transfer gossip: Cats and Middlesbrough submit loan offer for international winger
Marlos Moreno: Who is Sunderland and Middlesbrough transfer target and what has he said about Manchester City future?
Phil Smith's Sunderland player ratings as Cats lose at Sheffield Wednesday in Carabao Cup tie
The Sunderland team to face Sheffield Wednesday - predicted XI
Sunderland boss Alex Neil delivers this very honest verdict on cup exit and what went wrong
"Football is not exact science, you don't always get your reward instantaneously, it's just having the will to keep doing it.
"From the players and the staff they've kept persevering with it and not ever chucking it or giving up on it."
Sunderland have struggled to break teams down from open play in recent weeks, adding even more importance dead-ball situations.
And with the Black Cats fighting for promotion from League One, Ross hopes his side can improve all aspects of their game.
"It is evident within the group, the playing staff and the support staff involved in it, it is evident from them getting rewards from set-pieces because it's important," added Ross.
"The last two games it's earned us the two draws and they'll continue to play an important part for the remainder of the season.
"There are loads of other facets in football that we work on every single day, sometimes you see the evidence on the pitch, sometimes you don't.
"You've got to have the willingness to keep doing them everyday."