Good observation - my boy noticed the same - he also said we went back to 3 at the back at 2-2.
We can I suppose question why we went to 4-5-1, but well done the the management and players in being able to change it again and then step up to win the game.
UTB
Obviously I'm not a professional football manager, just a spectator and my opinion carries as much/little weight as anyone else's & I don't see the full picture, but the way I saw it was we scored on 51 minutes and for whatever reason didn't press home the advantage, and started to seriously struggle at around the hour mark. At that moment in time all that was needed was us to bring on fresh legs to re-reinforce the formation and tell Norwood to get 10 yrds up the pitch as he'd started to drop deeper and play less expansive passes which had the effect of hemming us in. We'd tired and dropped back and opened up an area of the pitch for Preston to play in that previously we'd controlled. So at 70 minutes, we should've taken Fleck, Duffy & Sharp off, bring Lundstram, Washington and Clarke on, dropping McGoldrick into a deeper lying role, but generally keep the same formation and play ourselves back into the game.
Sharp came off after 74 and we brought Johnson on and went 4-1-4-1. A flat back four of Stevens, JOC, Egan & Freeman. When I say went 4-1-4-1, it may have meant to be a 4-5-1, but basham was definitely playing in between the lines of the defence and midfield. At this point our shape was all over. Stevens & Johnson appeared to be playing the same position, Basham was unsure why Norwood was trying to play deeper than him & Duffy didn't know what he was meant to be doing. By going with a lone striker, we also allowed them to commit men and we couldn't make the ball stick up front & it was coming back a lot quicker. Also by changing the formation, we neutralised the marauding runs of Basham from RCB, which were were causing Preston problems. Our shape looked like a randomly tabbed word document, it was only a matter of time before Preston scored. I can't remember whether Henderson pulled a cracking save out at 2-0 or 2-1, but it was cracking save.
Duffy then gets subbed, much to Duffy's annoyance, and we seemed to go back to something like a 3-5-2 / 3-5-1-1, but it was really hard to work out what was going on, as Johnson seemed to be popping up on either flank (he delivered a beautiful cross from the right hand side to the far post, where he should've ideally been). We scored the 3rd, take McGoldrick off and go to what appears to be somewhere between a 5-1-3-1 and a four CB'ed 6-3-1 and hang on for 6 minutes of added time.