Fingering a 4-note straddle is similar to fingering a 3-note straddle, but of course you are dealing with 4 notes instead of 3, so a slightly different fingering is required. Play 2 of the 4 chord notes at once, leaving out the middle note, then play the remaining 2 notes, again leaving out the middle note. Pairing your 5th finger with your 2nd finger and your thumb with your 3rd finger works best for most people, although please remember that everyone’s hands are different in size and shape. Watch the short video as I demonstrate using a minor 7th chord and then a minor 9th chord:

A straddle in piano playing is where you play a chord, but leave one note out of the chord — you “straddle” the note you leave out with other chord notes. Watch this 5-minute video and you’ll understand: