And when it comes to Aston Villa in recent seasons - one of those that was very much a hit was defender Tyrone Mings.
Back in January 2019, Dean Smith was looking to build on his squad in a bid for a promotion push.
He turned to Bournemouth on deadline day and brought in defender Tyrone Mings to bolster his backline.
It turned out to be a good move.
Mings, who had began in non league before moving to Ipswich Town and then on to the Cherries arrived on loan initially.
He played 18 times and scored two goals as Villa secured a play off spot and then earned promotion via the play offs.
Since then Mings has gone from strength to strength and been an ever present for Villa in the top flight.
And he also fought his way into the England squad - and now has 17 caps for his country.
Very much a deadline day hit.