This Left Angle Cross of Revolution is named for Gate 4 and Gate 49 rather than Gate 49 and Gate 4, the answering mind placed ahead of the principled rupture. Human Design reads Gate 4, from Hexagram 4, Youthful Folly, as the mental urge to supply answers and hypotheses to questions still open, and Gate 49, from Hexagram 49, Revolution, as the sense of what is acceptable, deciding whether an arrangement continues or is broken off. It sits in the Left Angle family, and Human Design reads that group as outward facing, less a chosen plan than a role other people keep handing back.
Its design half is Gate 8 and Gate 14, both exchanged in the same way. Gate 8 sits in the Throat and is read as the urge to contribute an individual style and stand publicly behind something that matters; elsewhere it pairs with Gate 1 in the channel of Inspiration. Gate 14 sits in the Sacral centre and is read as skilled power, the fuel that directs resources and effort toward worthwhile work; it pairs with Gate 2 in the channel of The Beat.
Reversing which gate carries the Sun puts an answering mind ahead of a principled rupture, while the design half still answers with the same individual contribution and sacral fuel. The hexagrams are ancient; the reversal and the Left Angle reading both belong to the modern system, dated to 1987.