Cruz has NO chance on a second ballot. His function is to force a second ballot, or rather, to give cover for having a second ballot instead of changing the rules to untie all the delegates on the first ballot. A second ballot will be used to select someone the GOPe has already decided on and that is someone who may not be even officially running.
Trump could prevail on a 2nd ballot if the delegates came to their sense, but Cruz simply doesn’t have enough delegates to do so.
It is the 3rd ballot and following that will allow GOPE creep to set in. JMHO.