( CNN ) -- Over the years , it seems that just about every format imaginable has been used for debates between presidential candidates . Lecterns . Chairs . No chairs . Tables . No tables . Open stages to walk around on . Moderators working solo , like Jim Lehrer at this year 's first presidential debate and Martha Raddatz at the vice presidential debate . Moderators with panels of reporters . Questions submitted by the audience . Questions submitted by viewers at home . Town halls , like the one that will be moderated by CNN 's Candy Crowley on Tuesday . Yet , 52 years after the first televised presidential debate , there still often seems something stilted and dry about some of them ( but not all : witness last week 's high-energy vice presidential debate between Joe Biden and Paul Ryan ) . Frequently , though , the staffs of the people running for the presidency negotiate the ground rules so fussily that the debates can at times feel like some sort of candidates ' cotillion . So what if , for one debate some year , it was agreed to try the one format that has not been tested ? The debate would still be 90 minutes in prime evening time . The proceedings would still be telecast live on all the networks . There would still be an audience in the auditorium . But there would be no moderator , and no panel of questioners . There would be no subject matter agreed to in advance . There would be no rules . None . At the top of the hour , the two candidates would come out onto the stage . There would n't even need to be an announcer making an introduction . And then . ... It would be up to them . They would have 90 minutes to talk to the audience , and to each other . To argue , and try to persuade , with no referee . It just might be fascinating . Their staffs , as campaign staffs will do , would have prepared them and would have come up with tactics for each of them to take over the debate . And you can bet that the two candidates would fall back on those rehearsed tactics . For about 15 minutes . But then they would realize that , with 75 or so minutes left , they had better figure out a way to talk about things with each other , and with the nation . It would be like when people get stuck in an elevator together : They talk because they have to . They may feel that they have nothing in common , but now they 're here . In the elevator suspended between floors , there 's no one but the two of them . Surprising things can be said and learned . There 's no blueprint . No script . If a presidential debate of this sort were to be attempted , the audience in the auditorium , and at home , might find out some things about the candidates they would never discern in a tightly formatted , moderated debate , or in a standard-issue stump speech . And the candidates might find out a few things about each other -- maybe even find some unanticipated common ground . Funny things can happen in an elevator that is n't going anywhere . Some of what unfolds might have little to do with the specific words that are spoken . Is one of the candidates overbearing and selfish in how he uses the time -- does he refuse to let his opponent get a word in ? That would be a good thing for the voters to know . Is one of the candidates lighthearted and easygoing as he deals with the empty minutes in the company of the person he is running against ? That would be instructive to see . Who 's the leader ? Who heats up ? Who is unflappable ? There are , after all , occasions when presidents meet one-on-one with powerful foreign leaders , with no one to guide the conversation . This might be a good approximation of that -- presidential candidates unplugged , on their own , with no escape hatch . ( Or the debate might instead turn out to be an approximation of a pro-wrestling cage match , in suits and ties instead of trunks . ) Of course , once candidates took part in one debate with this format , they and their staffs would undoubtedly devise a way to screw it up for the next time , to make it bland and suck all the life out of it . But for one night -- that first night it was tried -- it just might make for great , riveting viewing . Or -- let 's be candid -- it might turn out to be an utter flop , like the announcerless National Football League telecast that took place in 1980 , when NBC Sports , as an experiment , put on a regular-season game between the New York Jets and Miami Dolphins with no announcers or commentators -- just the sights and sounds of the action . The post-game consensus was that it was n't such a splendid idea at all . But two candidates , stuck in the presidential-debate elevator , depending on their own wits , intelligence and deeply held beliefs to carry the night ? With just the two of them to figure it all out , and the entire nation watching ? There is at least a chance that it could develop into one of the most spontaneous and illuminating evenings of politics ever televised . There 's only one way to find out . The opinions expressed in this commentary are solely those of Bob Greene .
Bob Greene : The first thing I noticed was that the water tasted like plastic. He suggests a debate between two candidates -- with no moderator . Voters would see how candidates deal with unpredictable situations , he says .