Shifting gears

When Doyle Brunson coined the term shifting gears it was a sophisticated play only known to experts. Today all advanced players know the term and many know when to use it. Tomorrow, in the future, this will be a intermediate concept.
Shifting gears is so basic. One changes speeds on a one-dimensional line. Hold'em is much too complex for best strategy to be one-dimensional. Shifting gears should be an integral part of an overall strategy.
Shifting gears only cover your range of preflop starting hands. This set of hands was always a function of many factors. These factors include number of players on the table, relative chip stack sizes, stack sizes in terms in big blinds, your starting position, have others all ready entered the pot, styles of the other players, etc. and etc. This would suggests a strong player is shifting gears from hand to hand. Sometimes during a hand.
Phil Ivey was asked of his strategy starting a new tourney.
Ivey replied that he had no preplanned strategy. He would
observe the table and adjust.
There isn't a fixed relationship between the weighting of
the importance of each variable affecting the opening of
hands. When your chip stack is large relative to the big
blind you may choose among many opening styles. If your
chip stack is very small you are restricted to jam or fold.
You should be shifting gears from hand to hand.