Strong Jump-Shift

In responding to opener's 1-level opening, a Strong Jump-Shift (i.e.: a jump in a new suit) is game forcing and shows slam interest.

It shows either a very good 6+ card suit or a good 4+ card suit with support for opener's suit.

Although SAYC specifies a strong jump shift, most experts play jump shifts either as invitational or weak, and many people play 2/1 Forcing which reduces or possibly eliminates the need for strong jump-shifts.