A different ballpark

From Fresh Dictionary

English

Noun

a different ballpark

1. ((idiomatic{{#if:|, {{{2}}}{{#if:|, {{{3}}}{{#if:|, {{{4}}}{{#if:|, {{{5}}}{{#if:|, {{{6}}}{{#if:|, {{{7}}}{{#if:|, {{{8}}}{{#if:|, {{{9}}}}}}}}}}}}}}}}}}})) Something totally unrelated or of a vastly different scale or scope.

   Playing Flight Sim and flying a real airplane are in a totally different ballpark.

Synonyms

A different kettle of fish