Postpublished at 20:25 British Summer Time 29 September 2017
Right, that's all from me, and for cricket this summer.
There's a little matter of the Ashes this winter. It all kicks off with the women on 26 October.
See you then.
England win series 4-0
England win with 12 overs to spare
Bairstow 141*, Roy 96, Root 46*
W Indies 288-6: S Hope 72, Gayle 40
Ball 1-94: England's third worst in ODIs
Kal Sajad, Justin Goulding and Stephan Shemilt
Right, that's all from me, and for cricket this summer.
There's a little matter of the Ashes this winter. It all kicks off with the women on 26 October.
See you then.
England captain Eoin Morgan: "I'm extremely proud. it's been a long summer, especially with the focus on the Champions Trophy.
"Since then our attitude and composure has been convincing in every aspect. The guys who have come in have done outstandingly well.
"Guys have gone on to get big scores, which is something we have wanted the batsmen to do. Collectively, we're coming together.
"Fielding isn't a concern, but it's an area to make an improvement. We want to be with the world's best and we're not there yet.
"For the World Cup, we can't always rely on the spinners in the middle overs. We have to get the ball moving sideways somehow."
Stand-in West Indies captain Jason Mohammed: "The guys batted well but it went wrong in the bowling department. We weren't anywhere near as consistent as we wanted to be. We had them under pressure but there were always boundaries."
Man of the series Moeen Ali: "I've tried to ride the wave as much as I could and thankfully it's paid off.
"I always look for the short boundary. I've worked hard. I've got my head around batting seven and eight and tried to make the biggest impact.
"It's great bowling with Adil. He takes more wickets and I try to bowl as tight as I can.
"I can't wait for Australia, I'm very excited. There's work to put in. Hopefully we go there and win."
Man of the match Jonny Bairstow: "I'm pretty pleased. It's nice to finish a long summer with some runs and head into the winter with confidence. You wait a long time for a first hundred and when it comes you want to capitalise.
"If selection doesn't go your way, you have to bide your time and take the chance when it comes.
"Both my partners outscore me. The way they go about it is so fantastic.
"I'll rest before Australia, take a couple of weeks off."
#bbccricket
DeltaDrift: Remember when Bairstow's bottom hand & baseball stance were mocked? He just needed confidence.
Soul Limbo plays for the last time this summer. TMS is off air. I'm feeling a bit sad.
Isa Guha
Ex-England seamer on BBC Test Match Special
The only time you could say that England didn't play their new brand of one-day cricket was the Champions Trophy semi-final. That was a real opportunity to get through to the final and it will be the only thing they will look back on.
Simon Mann
BBC Test Match Special commentator
West Indies have been thrashed in three of their games here. This was a sobering defeat for them.
Isa Guha
Ex-England seamer on BBC Test Match Special
England played quite brilliantly. Jonny Bairstow was simply outstanding. A couple of centuries at the top of the order - I don't think he'll move from that position any time soon.
Handshakes and cuddles all round. The England players are down the dressing-room steps, wearing smiles after a pretty difficult week. Jonny Bairstow even signs an autograph on his way to the dressing room. Nice touch.
Eng 294-1
Won with a maximum! One needed from the final ball of the over, so Joe Root plonks it for a straight maximum. England win by nine wickets with 12 overs to spare. They end the international summer with a 4-0 triumph in this one-day series.
Phil Tufnell
Ex-England spinner on BBC Test Match Special
England have been too good - they've been very clinical and have got all bases covered.
West Indies are barely picking the ball up cleanly. It's as if someone has rubbed it in washing up liquid. Bairstow cracks the returning off-spin of Ashley Nurse through the covers to bring the required runs down to single figures. Eight needed. Just one more over?
Text 81111
Do I still need to worry about England's battin' in Oz?
Garreth in Worksop
Bairstow 124, Root 38
It's getting slippy out there. The Windies are skidding around like contestants in Total Wipeout. Bairstow is looking to put them out of their misery, using a lot a of bottom hand to belt through the covers. England's highest individual score against West Indies is 130 - he'll cruise that. Just 20 to win now.
#bbccricket
Josh Roberts: Death. Taxes. Jonny Bairstow.
Bairstow 113, Root 37
West Indies haven't learnt much is this series. They keep trying to bowl short despite the fact that all of England's batsmen have gobbled up anything marginally short of a length. Rovman Powell's boundary fielding, a right boot stuck somewhere in the direction of the ball, isn't too clever either. It's the effort of a man who doesn't want to get his kit dirty. Ring the the bell, they're already done.
Isa Guha
Ex-England seamer on BBC Test Match Special
It's a brilliant way to finish the summer, with Bairstow taking his opportunity at the top. He is Mr Dependable - consistent and ruthless.