So, Gantz is of the Blue and White party. It does look like this race will be much tighter than the one from April.
The election in April ended in a tie with Likud and Blue and White each winning 31 seats. Netanyahu was given the first opportunity to form a government. He could not. Instead of turning the formation of the government back to the President so Rivlin could select another MK to form a government, Netanyahu disbanded the government itself, releasing all members of the Knesset, and called for new elections.
This was one of Netanyahu's greatest acts of chutzpah (to that date) because he broke with the very protocol that returned him to the premiership in 2009. Ten years ago Likud came in second to Kadima and when Tzipi Livni was unable to form a government Netanyahu ran to the head of the line insisting it was now his turn. The rest is history.
Netanyahu is running a flop sweat campaign. Likud's internal polling is scaring Netanyahu so he's taking (or attempting to take) preemptive action. He's attempted to have cameras set up in polling places in predominately Arab areas (remember "the Arabs are voting in droves").
https://www.timesofisrael.com/netanyahu-those-who-oppose-polling-station-cameras-want-to-steal-elections/This failed so he's ratcheted up his claim of voter fraud in Arab towns ahead of Tuesday's vote. "The elections chief has turned down Netanyahu’s request for an “emergency†meeting to discuss the premier’s claims of rampant voter fraud in the Arab community".
https://www.timesofisrael.com/elections-chief-turns-down-netanyahus-request-to-meet-over-election-fraud/He's got to control the outcome, even after the vote, because this time Netanyahu is running not just for his political life but to escape indictment, trial and possible imprisonment (remember Ehud Olmert; former PM's do go to prison in Israel).
Netanyahu's pre-indictment hearing is scheduled for October. The last Knesset failed to pass a law protecting a sitting PM from indictment. If Likud wins and Netanyahu is able to form a government this time, he will not let it fail again. Look for this to be the first act of the new Knesset under the next PM Netanyahu term.