Does experience matter?

Well does it?

Does experience matter within a squad on FM? Or can the team be full of new regens with no experience at all, but have the attributes to play well.

Experienced players tend to have better mental attributes than newgens, but it's still possible to be successful without them.

A team full of newgens are unlikely to play well together as they're all new to each other. Whereas an experienced team that's been together a while will know each other's style of play and have a bond with each other and play better.

Other than that though, if the attributes are all equal (As Kenco says, newgens tend to have lower mental attributes) including the hidden attributes that you can't see then the teams should play to the same standard.

Also it doesn't matter how fantastic your 17 year old wonderkid is, he won't be able to tutor anyone else. So it's worth having a few really good older players in your side to aid the development of any youngsters in your side.

Yeah as a 17 year old still needs to be tutored so he gains the nessercerry mental skills he needs to become world class and an experience player is better to be captain as he has more of an effect on young players

i also find that new/unexperienced players are more likely to become nervous or complacent during a match; and are not as consistent as experienced players.

I am currently running a save game with three full teams able to run on the pitch at anyone time, there is my senior squad (First XI) who are aged between 24 & 31 (The youngest players have forced themselves past the elder statesmen), majority of this side have been with me for 4-5 seasons already. Behind them are a bunch of old men 29-34 who have been forced out of their position and they also team up with a group of 22-25 year olds who are the second best at each position, they generally play Cup matches and the league games against easier opposition. Then the final team is my 17-20 year olds, most play reserves/youth games with the occasional senior game thrown in with injuries/suspensions or just poor match fitness plays a part, and they are being tutored by the oldest player in each of their positions with similar personalities, it is working well...though I am still fighting to get a Champions League Victory, our togetherness in the domestic season is second to none.

Experienced players tend to have better mental attributes than newgens

Was about to post this very sentence when I read the title and OP.

you'll never win anything with kids....

Attributes matter (seen and unseen). That's it.