Coming from guitar I have memorised many chord variations, and I felt this was acceptable as the shapes are the same along the neck (for most jazz chords). However, now that I’m learning piano I’m finding it hard to imagine remembering every different shape in every key, along with the myriad of inversions that are possible with 10 fingers. It makes me realise that we probably think about chords very differently, and I’d like to know how others approach playing/improvising well voice led complex chords with alternating inversions. I’m thinking like Bill Evans, or Robert Glasper kind of progressions.
It's true that piano doesn't offer the similarity between chord shapes that guitar does, though that's not true of all chords (i.e., those that have open strings). To play the same progression in multiple keys on guitar will also frequently involve rearranging patterns a bit.
Anyhow, advanced pianists often spend a lot of time practicing patterns in multiple keys, if not in all keys -- whether those patterns are scales or arpeggios or other patterns like chord progressions.
Eventually, with enough practice, one learns the "feel" of a key, and fingers just naturally tend to move to the correct notes of the scale in that key. If I'm playing in A major, my hands are just going to naturally put in the three sharps (F, C, G) of that key, without a lot of conscious thought. If I happen to play another black note or play a C-natural or whatever instead, it will just "feel wrong" to me, unless it's a deliberate accidental.
So, that's definitely part of it for those who improvise on piano. Beyond that, as I said, many pianists will spend a lot of time learning standard progressions in all keys (or at least the ones they are likely to play in). Once you can do a ii-V-I turnaround in all keys, you can throw it in anywhere. Experienced jazz pianists will have a repertoire of dozens of those common moves memorized, so combined with that "feel of a key" I mentioned earlier, they can often navigate similar progressions in any key relatively easily. Highly chromatic progressions often feel like "this voice is sliding down chromatically" and the "feel" of a chromatic scale is again something an advanced pianist just knows. I don't really need to think of where the black and white keys are if I'm doing a chromatic chordal slide up or down -- with enough practice, your hands just do it almost on "autopilot" for common chord shapes.
I'm sure the way different pianists "feel" this stuff or visualize it varies, but my guess is that most have a sense of the "feel" of a key, and they just map all the chords they use around that. Personally, I can think in a lot of different ways about chord representation -- I can instinctively execute chord relationships from chord symbols (like C to F to G7 or whatever), but also think abstractly about chord relationships within a key (e.g., as tonic to subdominant to dominant, or as Roman numerals as I to IV to V7). I'm guessing most pianists don't tend to think quite so abstractly about it and would struggle to recreate some complicated Roman numeral progression in a random key, unless they've practiced that. Instead, it's probably mostly about "feel" and how fingers naturally "slide" around to close notes in chord progressions while maintaining their center around a particular local key. Some other folks may have a more "atomic" sense of chord progression, where they just know how chords relate in terms of root, so if the root is descending by whole step and the type of the first chord is X and the destination chord is Y, they just know how it "feels" to move that way.
Ultimately, the most advanced improvisatory pianists probably take that basic repertoire of dozens of standard progressions and expand it to hundreds of motions/patterns that they can instinctively create on the fly. Combined with facility in any key through various exercises, it eventually becomes relatively easy to transpose with barely a second thought. But of course all of this takes years and years of practice for most people.
The only "shortcut" I can recommend is start early. A lot of piano method books start with only a few central keys and make take years to introduce all major/minor keys. If you're beginning to feel out chords, I'd recommend starting with a simple thing like a major triad and just practice moving it up chromatically through all keys. (C major, D-flat major, D major, etc.) Once you can do that, then try a really simple progression (V-I) in each key, gradually shifting it up and down. If you have a good sense of all major scales and key signatures, this should eventually "click." Then you can gradually start trying more complicated progressions. In the meantime, if you don't feel comfortable thinking in all keys just yet, take some simple chord progressions that go with a popular song or something and just transpose them into a few simple keys (C major to F major to G major and then add more). If you can immediately home in on basic progressions like ii-V-I or IV-V-I in a few keys, you can gradually expand that list and gain facility in others. Then gradually start adding other chords and patterns.
In addition to Athanasius' great answer is the fact that virtually every chord change involves at least one note which is static.
I encourage students to know what that note is for any two chords, and move fingers to the changed notes. Simple example - triads C and F. Common note C. L.H. - C E G, hold on to C, move to C F A. Practise with C on top instead - same idea.
But, as already stated, like on guitar, where patterns and shapes abound, they do also on piano - it's just that there are more of them! So more to learn, longer to master.
I think you shouldn't overstate the ease of guitar chords just because you can slide a non-open chord up and down the neck. That certainly is not the whole picture of playing chords on guitar.
Similarly don't discount the shape patterns that do exist on the keyboard. There are certain shapes that repeat like
D major or
Db major, etc.
A great deal of practical keyboard chord knowledge derives from 6 major triad shapes, 6 minor triad shapes, adding sevenths to those, and making half-step alterations to those chords.
Observing certain interval characteristics on the keyboard may help demystify the situation.
Octaves are always the same key color and the same physical spacing. (Notice how that isn't so simple on guitar where there are several fretting shapes to play an octave.)
Perfect fifths are the same key color except those involving
B F# &
Bb F) which will be opposite color.
Minor sevenths are always opposite colors except those involving
E. (The inverse is true for major sevenths. You can just invert to seconds and reverse the colors.)
Thirds and sixth are more of an even mix of key colors, but instead of continuing to look for shape or key color patterns you should become more comfortable with keyboard as just all chromatic half steps. When you make a move like
I V6 (close voicing) it should be thought of as major triad, bass descends a half step, the middle voice descends a whole step and whether you end up on black or white keys (the keyboard chord shape) should not be a concern.
Chromatic pattern drills may help get that fluid sense of the keyboard. You can play certain intervals - two notes in one hand - chromatically ascending/descending the keyboard, parallel doubled scales. You can do something similar but with full chords. Of course most harmony doesn't move in that parallel fashion, but the point would be getting your hands used to moving over the "topography" of the keyboard fluidly getting used to a sort of equality between the black and white keys. You can find piano methods books that show fingering for the chromatic scale in parallel thirds and sixths. With time I think such drills make chord shapes on the keyboard less of a concern.
For the basic inversions, work on seeing the thirds and fourths contained.
ie-- root is thirds.
1st inversion has third on the bottom, fourth on top.
2nd inversion has fourth on the bottom, third on top.
Practice moving the hand between those shapes and simply placing the fingers there. Improve economy of motion to each of those shapes (with very little shuffling or replacing of fingers).
Also note that C Major inversions have specific fingerings:
CEG is 135
EG C is 12 5
G CE is 1 35
Practice those shapes and finger swaps carefully. Do it finger by finger. Use repetition. Also notice how the G is played by 5, then 2, then 1. Notice how each note is played with different fingers.
Perhaps that's all too basic-- but engrain those and further shapes will be open for mastery. Do the same for chords with four notes: CEGB etc.