Punishing: Gray Raven research: plan on the guarantee, and pick a 100% rate-up
An S-Rank construct is 0.5% an attempt and guaranteed by attempt 60. At that base rate 74.4% of players reach the guarantee, so the guarantee is the number to save for.
In Punishing: Gray Raven construct research, the guarantee is the plan, not the fallback. An S-Rank construct has a 0.5% chance per attempt and is guaranteed by attempt 60. At that base rate, 74.4% of players get to the guarantee without an S-Rank. For most people, an S-Rank simply costs 60 attempts.
Why the guarantee does the work
The research page lists 1.9% as the S-Rank rate "including the guarantee", which averages out to about one S-Rank per 53 attempts. That average sits close to the guarantee because the base rate contributes so little. After 30 attempts, only 14.0% of players have an S-Rank. The rate does not climb before the guarantee. Attempt 59 has the same 0.5% as attempt 1, and the guarantee then arrives all at once.
At 0.5% a try, 74.4% of players reach attempt 60 with nothing. Save for the full guarantee, because you will probably need it.
The rate-up share decides who that S-Rank is
The guarantee promises an S-Rank. The rate-up share decides whether it is the construct you came for. Of the 13 standard construct research types, 9 give the featured construct 100% of the S-Rank slot. On those, the attempt-60 guarantee is a guarantee on the construct itself. Not every research type works that way. On Arrival Construct and Arrival Event Construct the featured construct gets 70%, so even the guaranteed S-Rank can be someone else. The remaining 2 (Member Target) feature no construct at all. If you can choose, spend on a 100% research.
The Fate variant: same rate, different shape
Construct research also comes in a Fate form, 10 research types in all. The Fate form raises the base rate to 1.5% but moves the guarantee out to attempts 80–100. Both forms state the same 1.9% including the guarantee. The Fate form hits early more often, but its worst case is further out. If you are saving toward a guaranteed copy, the standard form's attempt-60 ceiling is the smaller number to save for.
Every research type at a glance
All 32 research types collapse into a handful of shapes:
Weapon research runs on a different scale. A 6★ weapon is 5% an attempt and guaranteed by attempt 30, and target-weapon research gives the featured weapon 80% of the 6★ slot. So, unlike a 100% construct research, the guaranteed 6★ is not always the weapon you wanted.
Two research types sit apart from the rest. Uniframe research has a 5.00% base rate and a guarantee by attempt 10, for 12.45% including the guarantee. It is the most generous research in the game, though it is limited to Uniframe constructs. CUB research is 5.82% base, guaranteed by attempt 20.
The full reward breakdown of every research, down to the Cog Box and EXP material odds, is on the research odds page, and each research type's row is on research rates. To see what an S-Rank construct is worth at any level, use the construct stats calculator.