Chelsea manager Frank Lampard speaking to Sky Sports: "It is two points lost at the end of the day - and that's no disrespect to West Brom. You come here and you know the transition and any mistakes would be something they would jump on - that and set pieces. You can't legislate for the mistakes that there were today.
"It was mistakes, clear mistakes [that cost us]. You can have as many meetings as you want but with those mistakes you give yourself a mountain to climb. [We lacked] a bit if urgency in the team.
"We created two or three great chances in the first half. I felt we would create more, the only other problem at 3-0 was West Brom were going to protect their lead more. It is a big lesson for us. We will get a lot better, we're still finding our way with new players and a lack of pre-season. Today is part of the process of getting better.
"There is a lot we can keep getting better at. I'm not going to criticise every part of our game, I think they had three shots on target and got three goals. There were genuine mistakes. There was nothing tactically you can analyse again and again - there were just pure mistakes."
More from Frank Lampard, speaking with BBC Sport: "We have two big games coming up against Tottenham and Crystal Palace. I expect to see an improvement in our performances. But in terms of team fitness, it won't be until after the international break that I expect to see us up to our real level, especially in terms of on the ball, because we haven't had time to work on that yet."
West Brom manager Slaven Bilic speaking to BBC Match of the Day: "It was a good game. Six goals. Really proud of the way we played - how we attacked first half, how we forced them to play, how we ran, defended, were focused. Really good.
"Second half we knew they would come at us. We wanted to limit them to shots outside the box and stop them crossing.
"One of their shots went in. Great strike, but we deserved to get three points.
"It's not always about what you want to do, sometimes it's about the opposition. Chelsea are great players. We wanted to have more time on the ball and wanted to score more goals. Occasionally we had good moments and created good chances. With a bit of luck we could have won 4-2, but we knew we would have to defend deep in the second half and I thought we were excellent."
On West Brom's start: "Three games so far against Leicester, Chelsea and Everton. A tough schedule, but I have taken plenty of positives in all the matches.
"Now we have to find the belief and confidence that we belong here and have a genuine chance to stay up."
Chelsea striker Tammy Abraham speaking to Sky Sports: "In the first half we made it difficult for ourselves. I had a chance I should have put away and one I should be taking at this level. They scored from every shot. We knew we had to come out in the second half and not drop our heads - and that's what we did."
On what manager Frank Lampard said at half-time: "We all went in and our heads were down and he had to lift us up. He said we didn't look like a team ready to go out and win and we needed to pick each other up in the second half. Thankfully Mason [Mount] got the goal which meant we could believe. I knew we'd get chances but to come back from 3-0 is never easy. The boys deserve credit, they kept going."
On lessons to take away: "We need to cut out the mistakes as a team so we don't concede. We need to be strong together and keep encouraging one another."