[{_id:ObjectId("5db85ee97d9fb13ead4fc54c"),applId:ObjectId("5d48f34f7d9fb10ce171f905"),fileId:"dd386cf7-4139-45c2-9853-cbb126621b51",job:{},country:"US",fullName:"abcd xyz",htmlWordCount:2766,textWordCount:1867,rchilliTextWordCount:2840,deleted:0,dateEntered:ISODate("2019-10-29T15:46:49.237Z"),dateModified:ISODate("2019-10-29T15:46:49.237Z")}]

db.collection.aggregate([{$match:{country:"US"}},{$project:{country:1,fullName:1,htmlWordCount:1,textWordCount:1,rchilliTextWordCount:1,winner:{$switch:{branches:[{case:{$and:[{$gt:["$htmlWordCount","$textWordCount"]},{$gt:["$htmlWordCount","$rchilliTextWordCount"]}]},then:"htmlWordCount"},{case:{$and:[{$gt:["$textWordCount","$htmlWordCount"]},{$gt:["$textWordCount","$rchilliTextWordCount"]}]},then:"textWordCount"},{case:{$and:[{$gt:["$rchilliTextWordCount","$htmlWordCount"]},{$gt:["$rchilliTextWordCount","$textWordCount"]}]},then:"rchilliTextWordCount"}],default:"No winners"}}}}])