Springfield recieves the visit of Dalhia Brinkley, a former student who graduated from Yale. Lisa comes in and Dalhia encourgages her to be in more extra-curricular activities. So at home she is practicing fencing with Maggie, when Maggie snapped and beaten her..in Zorro style. Flanders dropped by saying he won't be Bart's baseball coach anymore as the referee called a homerun when it really was a foul. (Homer: Flanders, don't you have another neighbour? Flanders: Yes I do! And I love him just as much as you! It's a FLanders sandwich with the best neighbour bread!) so Marge protests saying someday Bart and Lisa wont' be around and he'll regret not spending time with them, and Homer says it's a problem for future Homer and drinks a mix of vodka and mayonnaise (and faints).
At the baseball court Bart sees the team practicing and learns the team got a new coach - Lisa! But she doesn't know about baseball:
Bart: Need more research tootsie-pop
Nelson: Get a room!
Lisa: We're brother and sister
Milhouse: So are my parents, I think...
And Lisa gets advice from Frink and the nerds who where having out at Moe's (Moe: Why did I advertise my drinks in scientific American? Frink: I can think of 3 good reasons... Moe: Shut up). And then we have Matrix-eque montage of the team winning (Raplh - I caught a white apple!) and then we get to a game were if Bart doesn't swing they win, but Bart is mad at Lis for ruining his fav sport, and swings anyways and they win, and Lisa kicks him off the team (as the team would say: "conflicted! conflicted!")
So at Luigi's everyone is mad at Lisa but Lisa says that players play and managers manage (and Raplh asks if alligators alligate, and Lisa says they do, and Raplh says he's Scared, LOL). So back at home, Bart gives his uniform to Lisa and Homer thinks they'll have an underpants dinner. Then we have a hilarious exchange between Homer and Marge:
Marge: Family is forever
Homer: Homer: Sorry Marge. I gotta call bullcrap on that one. The '69 Mets will live on forever, but you think anybody cares about Ron Swoboda's wife and kids? Not me, and I assume not Ron Swoboda.
Marge: But aren't you worried about Bart's feelings?
Homer: Boys don't have feelings, they have Muscles!
Marge: Why do you say such ridiculous things?
Homer: They sound good in my brain, but my tongue makes the words not sound very good...formally!
So Bart tries to be co-commentarist while the Isotots get to the championship match in Capital City. Homer and Lisa leave in the stadium and Marge takes Bart to an amusement park. There at a rollercoaster, Lisa calls Bart, telling him he needs another player as Ralph can't play because he it too juiced (Raplh: I didn't know what I was putting into my body!), and Mike Scioscia convinces Bart to listen to Lisa and return.
There, at the stadium Bart returns and steals 2nd and 3rd base, and he is about to steal home when Lisa shouts the computer says it's impossible, and we see Burns saying that they'll never replace his old calculator (which is huge) and Smithers says it's stuck and Burns' tells him to apply more goose grease. Bart is about to steal home (Homer: If he makes it that's my son!) when suddenly he is out (Homer throws his foam finger at him, shouting You STiNK!) and everyone leaves. Lisa tells him how he made her enjoy baseball (Lisa: You made me love baseball. Not as a collection of numbers, but as an unpredictable, passionate game, beaten in excitement only by every other sport.) and that he is a good brother 51% of the time. Bart says his guy tells him she's good too, but she demands a number, so Bart gives her Homer's foam finger (which has a #1) and the hug. The team comes and say "conflict resolved! conflict resolved!" and it ends.
Bottom line: It was a great episode with lots of funny lines, and a very dark (but amusing) couch gag. This season is going very well till now (excluding the premiere). 9/10.