Is your baseball glove a relic from your youth, purchased back when digital watches were expensive and gas was cheap? If so, it probably needs some new lacing. You could buy a new glove, of course, but repairing your old one is so much more satisfying. With a little care, this glove could be passed on to your kids.
Treat the new rawhide lacing with a leather softener or glove oil before you begin work. This will allow the leather to soften and make it easier to handle.
Inspect the lacing and memorize the lacing pattern.
Remove one section of the broken lacing (see A). If necessary, use a pair of scissors to cut it free.
Tie a simple overhand knot at one end of a long piece of the new rawhide lacing. Pull the knot as tight as possible.
Using a leather awl, ice pick or other pointy tool, push the lacing through the first hole in the stitching pattern (see B). Pull the lacing through, up to the knot in its end.
Continue threading the lacing through the holes, following the lacing pattern of the original. Pull the lacing as tight as possible without deforming the glove. The lacing will stretch over time, so tightness is essential to a lasting repair.
Place another overhand knot in the lacing at the end of the section. Adjust the knot so that it is snug against the glove. Cut off any excess lacing.
Continue working on other sections as needed.