N.J. hospitals were predicted to hit "peak capacity” last Saturday, the day they would be inundated with the highest number of coronavirus patients — more than 14,000, with one in five of them fighting for their lives in the intensive care unit, according to the state’s health commissioner.

That prediction, based on statistical modeling, didn’t come true.

On Tuesday, state Health Commissioner Judith Persichilli gave a different estimated peak target date and an even bigger anticipated surge number: 16,000 patients on April 25, including 3,821 in the ICU.

“And this (number) will change tomorrow,” Persichilli said.

Every day, New Jersey — like every other state in the nation — is engaged in a high-stakes, complex guessing game based on mathematical models that are unlikely to ever be 100 percent accurate since the data keeps changing.

Gov. Phil Murphy has said since the beginning of the crisis that the objective is to prepare for the worst. The state has worked aggressively to build capacity. New Jersey’s 71 acute-care hospitals have added 60% more beds and doubled the number of critical care beds from just under 2,000 to 4,000 in about three weeks.

“We are trying as best as we can to figure out where this is headed,” Murphy told reporters during his daily coronavirus press briefing in Trenton on Tuesday.

“If the best-case scenario comes to pass, the amount of beds — both generally and ICU — the ventilators and please God, the fatalities, will be lower, but the peak will come later,” he added.

“If this is the worst case, I think our hospitals are very prepared to take care of the individuals,” Persichilli said.

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New Jersey, a state of 9 million residents, has tested 129,400 people. Of them, 68,824 have been determined to have COVID-19 and 2,805 have died, state officials announced Tuesday. Only New York has more positive cases and deaths among U.S. states.

The state has estimated its need for hospital beds, ventilators and personal protective equipment by relying on statistical models that factor in the social-distancing actions the governor mandated on March 21, said Beth Noveck, New Jersey’s Chief Innovation Officer.

The state is using a variation of the Susceptible-Infected-Recovered or SIR model, and the Susceptible, Exposed, Infected and Resistant or SEIR model, both of which have been used previously to track infectious diseases. They are similar to the model developed by the Washington Institute for Health Metrics and Evaluation that has been widely referenced by public health officials during the coronavirus pandemic, according to the governor’s office.

“What this means in plain English is that we take into account what happened in other countries including China and Italy and tailor them to the variations observed at a county level in New Jersey,” Noveck said.

“Additionally, we rely not only on the confirmed positives through testing, but also on data observed in hospitals,” Noveck said. "A combination of these models collectively yields highly accurate predictions over 10-day forecasts as well as provide forecasts for expected case, best-case and worst-case scenarios in the long term.”

Hospitalizations rose 4% between Monday and Tuesday, Persichilli said. That can be attributed to a rise in the number of COVID-19 patients coming from nursing homes and veterans homes, Noveck said.

Murphy said it is O.K that peak estimates keep changing because it’s clear social distancing measures and closing schools and businesses are keeping the infection rate in check.

“I would love nothing more than to someday look back and say we over-prepared,” the governor said during his press briefing Monday. “That’ll be the best mistake any of us ever made. But we don’t have that luxury right now. Because we know that if we stop doing what we’re doing, even one bit, COVID-19 can boomerang on us and bring about the worst-case scenario. So let’s stick together and let’s keep working together.”

NJ Advance Media staff writer Brent Johnson contributed to this report.

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Susan K. Livio may be reached at slivio@njadvancemedia.com. Follow her on Twitter @SusanKLivio.