One of the most popular synonyms for "inning the cards" is "in the bag," as it also suggests a sense of inevitability and certainty. Other synonyms that convey a similar sentiment include "a done deal," "a foregone conclusion," and "a slam dunk." Another option is "to have something in one's pocket," which implies a sense of control and ease. Additionally, "to have something in the can," "to have something sewn up," and "to have something wrapped up" all suggest that the outcome is certain and cannot be changed. Overall, there are several synonyms that can be used to communicate the idea that something is likely to happen with a high degree of certainty.