Before the AFPRB, about 1970-71, pay was set by the Grigg Committee. Invariably it was sold as 7% - 4% this year and 3% next. Any fool could see the error in the maths (GCE days of course).
With the advent of AFPRB, and the rampant inflation under Ted Heath when we had monthly pay rises as well, we got the annual pay round. All Calaghan tried to do was revert to the Grigg formula of a fixed price deal in the hope that inflation would rise but we would be in a wage increase fix.
The civil service secured a 5-year fix (just ended) under the grumpy jock which was really a bet on inflation. I think it just about worked out OK. The GJ got his own back this time with a 2.5% deal. Not enough to buy a pint even.