Pikachu's CGs are awesome in this match-up but aren't the solution to all of our problems since our grab range is so small.
First, we need to figure how to get the grab. Falco’s ftilt, shine, jab, grab,dtilt(?) keep us away from grabing him.
I’m mostly getting grabs from fair>grab, or punishing his landing/baiting an aerial ocasionally a tripping dtilt > grab happen, especially since it's my prefered spacing tool. Utilt>grab don’t really work for me since I find hard to enter enough in the **** bird comfort zone to use the utilt.
Probably he will get the CG on us sometime, respect the chain and don't try to jump out of it. When he dAir, DI and Tech the stage/ledge or get back with a QA, reset the match and play smart.
IF we get the CG on them, we have an advantage, learn to work with marginal advantage. Don't go greedy on kill moves, take your time crouch, dtilt and punish when he mess up with kill move or a quick GTFO to send him offstage and gimp, just remember to hit him at the starting OR ending frames of the Phantasm. Get into his play style and crack him.
Remember the common Falco play style is abusable. He'll stay on the defensive with lazors and try for a grab like against everybody, disrupting game with a jab now and then. The diference in this match-up is that he'll be using ftilt a lot more. Approach wisely, powerwalk or just crouch if the stage let you crouch under lazers, slided dtilt him and retreat. Only jump for the grab if the opportunity arises, he'll try to mindgame you into exposing yourself, play safe.
Falco will also aim for a CG to build damage, and may end with a meter or a dacus-like combo (dash attack>usmash). Lazer spam is a no brainer and he’ll use it, on stages like pictochat crouching may no solve your problems with it, so learn to power shield. Watch for tilts, jabs and some shines, expect Phantasms to be used as a runaway tool. His aerial game is not that good so getting him on the air is a good idea, abuse your Uair.
When he start going to the kill, expect three things: Bair, Usmash or Fsmash “gimp”. I see Bair as the easier killing move that Falco has, but Pikachu survive well to the sides, so when you’re at killing %, secure the center of the stage and read his attempts to Usmash.
My thoughts: One of Falco’s hardest match-ups, we’re pretty to him like Marth is to us – we’re one of his counters but not a real hard counter, exactly 60-40 , he’s in the same league but harder than Link.