十之[有]八九 [- zhī bā jiǔ]nine in ten; in all probability; in eight or nine cases [chances] out of ten; ninety nine out of a hundred; ten to one — most likely:
•¶十之[有]八九他失信了。 Most likely he has broken his promise.
•¶ 他十之[有]八九乘火车来。 Nine times out of ten he would come by train.