Two years, two partners and once again Leander Paes loses in Round Two. It’s obviously not his lucky number at the Chennai Open but Paes, typically, is blase about it. ‘‘Frustrating? No way. Defeats, I’ve seen a lot of them.’’Last year it was Nenad Zimonjic, this time it’s Martin Damm, an acquaintance from the time they were both junior players.As the sixth best team on the ATP Doubles Race last year, making three finals in their last five events including the Masters Cup in Shanghai, Paes obviously has warm thoughts of Zimonjic. While Zimonjic was a younger to Damm, Paes explains why he joined forced with an older player, especially when he’d said that he wanted to play with someone younger.‘‘For me at this stage, tennis is all about passion. I seek different experiences before I retire. I’ve been in the leader’s role for quite some time. Now, Martin can play the elder bro, while I can be more creative.’’However, unlike with the Serb, Paes is reluctant to commit long-term to Damm. ‘‘We are trying thing out’’, he says, before explaining why this would be an experimental partnership. ‘‘He’s a great guy, communicates well — he calls a spade a spade — and is a good human being, but a year is a long time to commit to.’’‘‘I’m a bit systematic about choosing partners’’, he says, then adds, ‘‘I’ll enjoy working with Damm, he’s done well under the circumstances.’’So what is he choosy about? ‘‘I need someone who can complement me on court. Doubles is all about that.’’ Damm (33) has a good serve, something Paes needs in his mission to better the No 5 rank he attained in doubles last year.For his part, Damm acknowledges that Paes is the more experienced — and also the more technically adept on court. ‘‘The trick is in putting these two factors together and building a partnership’’, Damm explains.One stumbling block in their relationship, Paes feels, is the new set of ATP doubles rules. Essentially it makes for shorter matches, and is skewed towards more attacking play. ‘‘It favours the underdogs’’, Paes says, ‘‘but I’m hoping that it will be reviewed in the next three months.’’‘‘Given that, and the fact that Damm is experienced, I’m following a wait and watch policy on the partnership.’’And if the rules remain? ‘‘Well, we are already playing. Probably we, by then, could adapt as well so that the partnership could continue.”