{
  "schemaVersion": 1,
  "edition": 2026,
  "lastReviewedDate": "2026-07-16",
  "objectives": [
    {
      "id": "power_comfort",
      "label": "Power & Comfort",
      "rangePosition": "lower"
    },
    {
      "id": "balanced",
      "label": "Balanced All-Court",
      "rangePosition": "middle"
    },
    {
      "id": "control_spin",
      "label": "Control & Spin",
      "rangePosition": "upper"
    }
  ],
  "constructions": [
    {
      "id": "polyester",
      "label": "Polyester / co-poly",
      "baseRangeLbs": { "min": 44, "max": 54 },
      "objectiveRangesLbs": {
        "power_comfort": { "min": 44, "max": 48 },
        "balanced": { "min": 47, "max": 51 },
        "control_spin": { "min": 50, "max": 54 }
      },
      "playableHours": { "min": 10, "max": 20 },
      "note": "The stiffest common construction. Start below an equivalent nylon or gut reference and prioritize comfort if you are new to poly."
    },
    {
      "id": "hybrid",
      "label": "Hybrid",
      "baseRangeLbs": { "min": 46, "max": 56 },
      "objectiveRangesLbs": {
        "power_comfort": { "min": 46, "max": 50 },
        "balanced": { "min": 49, "max": 53 },
        "control_spin": { "min": 52, "max": 56 }
      },
      "playableHours": { "min": 15, "max": 26 },
      "note": "Use the frame range as the guardrail and normally string a polyester component about 2 lbs (1 kg) below the softer string."
    },
    {
      "id": "synthetic_gut",
      "label": "Synthetic gut / nylon",
      "baseRangeLbs": { "min": 50, "max": 60 },
      "objectiveRangesLbs": {
        "power_comfort": { "min": 50, "max": 54 },
        "balanced": { "min": 53, "max": 57 },
        "control_spin": { "min": 56, "max": 60 }
      },
      "playableHours": { "min": 20, "max": 35 },
      "note": "A practical reference construction with moderate comfort, power, and durability."
    },
    {
      "id": "multifilament",
      "label": "Multifilament",
      "baseRangeLbs": { "min": 50, "max": 60 },
      "objectiveRangesLbs": {
        "power_comfort": { "min": 50, "max": 54 },
        "balanced": { "min": 53, "max": 57 },
        "control_spin": { "min": 56, "max": 60 }
      },
      "playableHours": { "min": 25, "max": 40 },
      "note": "A softer, elastic construction suited to players who prioritize comfort and accessible power."
    },
    {
      "id": "natural_gut",
      "label": "Natural gut",
      "baseRangeLbs": { "min": 50, "max": 60 },
      "objectiveRangesLbs": {
        "power_comfort": { "min": 50, "max": 54 },
        "balanced": { "min": 53, "max": 57 },
        "control_spin": { "min": 56, "max": 60 }
      },
      "playableHours": { "min": 30, "max": 50 },
      "note": "The most elastic construction here and the strongest tension holder, but it needs protection from moisture and abrasion."
    }
  ],
  "sources": [
    {
      "id": "wilson-starting-ranges",
      "publisher": "Wilson Sporting Goods",
      "title": "What String Tension Should I Use in My Tennis Racket?",
      "url": "https://www.wilson.com/en-us/blog/tennis/how-tos/what-string-tension-should-i-use-my-tennis-racket",
      "accessedDate": "2026-07-16"
    },
    {
      "id": "babolat-objectives",
      "publisher": "Babolat",
      "title": "How to choose your tennis string",
      "url": "https://help.babolat.com/hc/en-us/articles/16467763347613-How-to-choose-your-Tennis-String",
      "accessedDate": "2026-07-16"
    },
    {
      "id": "itf-string-construction",
      "publisher": "International Tennis Federation",
      "title": "Rackets and Strings — Strings",
      "url": "https://www.itftennis.com/media/2175/rackets-and-strings-strings.pdf",
      "accessedDate": "2026-07-16"
    }
  ]
}