In most civil cases/lawsuits as well as administrative hearings, a party must prove its claim or position by a preponderance, defined as a superiority in weight, force, importance, etc. In legal terms, a preponderance of evidence means that a party has shown that its version of facts, causes, damages, or fault is more likely than not the correct version, as in personal injury and breach of contract suits. This standard is the easiest to meet and applies to all civil cases unless otherwise provided by law.
The concept of “preponderance of the evidence” can be visualized as a scale representing the burden of proof, with the totality of evidence presented by each side resting on the respective trays on either side of the scale. If the scale tips ever so slightly to one side or the other, the weightier side will prevail. If the scale does not tip toward the side of the party bearing the burden of proof, that party cannot prevail.
Trial lawyers will often instruct juries that their clients must prevail at trial if they have proved their positions by as little as 51 percent likelihood of probability (anything from 51 to 100 percent constitutes a preponderance of evidence). In other words, if a jury believes there is a 51-49 percent likelihood that a defendant (in a civil case) was negligent or liable, the plaintiff/complainant has met its burden of a preponderance of evidence, and will prevail. This is particularly helpful when juries are torn between the testimony of two expert witnesses presenting opposite opinions or views. Whether it is an issue of credibility or of expertise, the jury will decide which is the more likely version that warrants more evidentiary weight.